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Sample records for aluminum sodium fluoride

  1. Selective Adsorption of Sodium Aluminum Fluoride Salts from Molten Aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Leonard S. Aubrey; Christine A. Boyle; Eddie M. Williams; David H. DeYoung; Dawid D. Smith; Feng Chi

    2007-08-16

    Aluminum is produced in electrolytic reduction cells where alumina feedstock is dissolved in molten cryolite (sodium aluminum fluoride) along with aluminum and calcium fluorides. The dissolved alumina is then reduced by electrolysis and the molten aluminum separates to the bottom of the cell. The reduction cell is periodically tapped to remove the molten aluminum. During the tapping process, some of the molten electrolyte (commonly referred as “bath” in the aluminum industry) is carried over with the molten aluminum and into the transfer crucible. The carryover of molten bath into the holding furnace can create significant operational problems in aluminum cast houses. Bath carryover can result in several problems. The most troublesome problem is sodium and calcium pickup in magnesium-bearing alloys. Magnesium alloying additions can result in Mg-Na and Mg-Ca exchange reactions with the molten bath, which results in the undesirable pickup of elemental sodium and calcium. This final report presents the findings of a project to evaluate removal of molten bath using a new and novel micro-porous filter media. The theory of selective adsorption or removal is based on interfacial surface energy differences of molten aluminum and bath on the micro-porous filter structure. This report describes the theory of the selective adsorption-filtration process, the development of suitable micro-porous filter media, and the operational results obtained with a micro-porous bed filtration system. The micro-porous filter media was found to very effectively remove molten sodium aluminum fluoride bath by the selective adsorption-filtration mechanism.

  2. Fluoride Removal From Drinking Water by Electrocoagulation Using Iron and Aluminum Electrodes

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    Takdastan

    2014-07-01

    Full Text Available Background Existence of fluoride in drinking water above the permissible level causes human skeletal fluorosis. Objectives Electrocoagulation by iron and aluminum electrodes was proposed for removing fluoride from drinking water. Materials and Methods Effects of different operating conditions such as treatment time, initial pH, applied voltage, type and number of electrodes, the spaces between aluminum and iron electrodes, and energy consumption during electrocoagulation were investigated in the batch reactor. Variable concentrations of fluoride solution were prepared by mixing proper amounts of sodium fluoride with deionized water. Results Experimental results showed that aluminum electrode is more effective in fluoride removal than iron, as in 40 minutes and initial pH of 7.5 at 20 V, the fluoride removal process reached to 97.86%. The final recommendable limit of fluoride (1.5 mg/L was obtained in 10 minutes at 20 V with the aluminum electrode. Conclusions In electrocoagulation with iron and aluminum electrodes, increase of voltage, number of electrodes and reaction time as well as decrease of the spaces between electrodes, enhanced the fluoride removal efficiency from drinking water. In addition the effect of pH and initial concentration of fluoride varied with types of electrodes.

  3. How and when to prescribe sodium fluoride.

    Science.gov (United States)

    Shambaugh, G E

    1989-03-01

    Sodium fluoride has now been used for 24 years in an effort to slow down or arrest sensorineural hearing nerve deterioration in patients with stapedial otosclerosis or after stapedectomy, as well as in patients with pure cochlear otosclerosis. Extensive clinical experience in thousands of patients with this therapy has demonstrated its value in arresting previously progressive sensorineural hearing loss. For a long time there were those who objected to this therapy on the basis that it had not been adequately proven by double-blind, placebo-controlled studies. They have been answered by Bretlau's study in Denmark and Fisch's from Switzerland; both investigators confirmed on small groups the value of sodium fluoride by double-blind, placebo-controlled studies. Extensive research by Professor Petrovic of Strasbourg while at our tissue culture laboratory at Northwestern University demonstrated the action of sodium fluoride on bone. A nicely designed study with radioactive strontium by Linthicum, House, and Althaus demonstrated its value in promoting maturation of a spongiotic focus. Today there is no reason to hesitate in prescribing this useful, effective, and safe medication to promote maturation of otospongiotic lesions, and thus to slow down or to arrest progression in sensorineural hearing loss.

  4. Fluoride and aluminum in teas and tea-based beverages

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    Hayacibara Mitsue Fujimaki

    2004-01-01

    Full Text Available OBJECTIVE: To evaluate fluoride and aluminum concentration in herbal, black, ready-to-drink, and imported teas available in Brazil considering the risks fluoride and aluminum pose to oral and general health, respectively. METHODS: One-hundred and seventy-seven samples of herbal and black tea, 11 types of imported tea and 21 samples of ready-to-drink tea were divided into four groups: I-herbal tea; II-Brazilian black tea (Camellia sinensis; III-imported tea (Camellia sinensis; IV-ready-to-drink tea-based beverages. Fluoride and aluminum were analyzed using ion-selective electrode and atomic absorption, respectively. RESULTS: Fluoride and aluminum levels in herbal teas were very low, but high amounts were found in black and ready-to-drink teas. Aluminum found in all samples analyzed can be considered safe to general health. However, considering 0.07 mg F/kg/day as the upper limit of fluoride intake with regard to undesirable dental fluorosis, some teas exceed the daily intake limit for children. CONCLUSIONS: Brazilian and imported teas made from Camellia sinensis as well as some tea-based beverages are sources of significant amounts of fluoride, and their intake may increase the risk of developing dental fluorosis.

  5. [Allergy caused by sodium fluoride glycerin: a case report].

    Science.gov (United States)

    Ma, Jihong

    2012-04-01

    In recent years, though more and more ulcerations of oral mucosa caused by allergy to drug occurred clinically, allergy to sodium fluoride glycerin is extremely rare. A case of allergy to sodium fluoride glycerin occurred in Qianfoshan Campus Hospital of Shandong University. After treatment by sodium fluoride glycerin, there was mucosal edema, a large number of red miliary granules in buccal and palatal mucosa. After 3 hours, there were swallowing difficulties, but no breathing difficulties. Next day large ulcers of oral mucosa developed. The patient was cured 7 days after treatment. Fluoride-sensitive test result was positive.

  6. Uses of sodium fluoride varnish in dental practice.

    Science.gov (United States)

    Chu, C H; Lo, Edward

    2008-06-01

    Fluoride varnish is developed to prolong the contact time between fluoride and tooth surface, so that the tooth becomes more resistant to caries attack. The active ingredient of fluoride varnish is usually 5% sodium fluoride, (22,600 ppm fluoride). Studies have found that fairly insoluble globules of calcium fluoride-like material formed on the tooth surface after topical fluoride application. These globules act as a reservoir of fluoride in the mouth for a prolonged period of time. Systematic reviews corroborate evidence for the efficacy of fluoride varnish in the prevention of dental caries. Sodium fluoride varnish is used to prevent caries development, arrest early enamel and even soft dentine caries through promotion of remineralization of carious tooth substance. It is also used to treat tooth hypersensitivity. Some use it as a provisional luting agent by itself or combined with other provisional luting agents for cementing provisional crowns. Fluoride varnish has recently gained much attention in dentistry because it is quick and easy to apply. It sets rapidly on teeth, and gagging and swallowing is unusual. Side-effects or complications of its use are rare. Studies show that fluoride varnish is safe for young children and the risk of dental fluorosis is minimal. The simplicity of its application makes it very suitable and practical for use in dental clinics and outreach dental services, especially in young children and in other special needs groups.

  7. 21 CFR 582.1781 - Sodium aluminum phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium aluminum phosphate. 582.1781 Section 582.1781 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Additives § 582.1781 Sodium aluminum phosphate. (a) Product. Sodium aluminum phosphate. (b) Conditions...

  8. 21 CFR 182.1781 - Sodium aluminum phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium aluminum phosphate. 182.1781 Section 182.1781 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1781 Sodium aluminum phosphate. (a) Product. Sodium aluminum phosphate....

  9. [(18)F]-Sodium fluoride uptake in Takayasu arteritis

    NARCIS (Netherlands)

    Alexanderson-Rosas, E; Monroy-Gonzalez, A G; Juarez-Orozco, Luis Eduardo; Martinez-Aguilar, M M; Estrada, E; Soldevilla, I; Garcia-Pérez, O; Soto-Lopez, M E

    2016-01-01

    BACKGROUND: While (18)F-fluorodeoxyglucose and (18)F-sodium fluoride with positron emission tomography relate with inflammation and calcification, their role in the assessment of patients with Takayasu arteritis has not yet been studied. METHODS: We present 5 patients with suspected active metabolic

  10. Pharmacokinetics of Fluoride in Toddlers After Application of 5% Sodium Fluoride Dental Varnish

    OpenAIRE

    Milgrom, Peter; Taves, Donald M.; Kim, Amy S.; Watson, Gene E.; Horst, Jeremy A

    2014-01-01

    The prevalence of dental caries (tooth decay) among preschool children is increasing, driven partially by an earlier age of onset of carious lesions. The American Academy of Pediatrics recommends application of 5% sodium fluoride varnish at intervals increasing with caries risk status, as soon as teeth are present. However, the varnishes are marketed for treatment of tooth sensitivity and are regulated as medical devices rather than approved by the US Food and Drug Administration for preventi...

  11. Effects of fluoride and aluminum from ionomeric materials on S. mutans biofilm.

    Science.gov (United States)

    Hayacibara, M F; Rosa, O P S; Koo, H; Torres, S A; Costa, B; Cury, J A

    2003-04-01

    Ionomeric materials release different proportions of fluoride and aluminum. Their simultaneous effect on the acidogenicity and composition of S. mutans biofilm is unknown. Six cylindrical specimens of each material (Ketac-fil, Vitremer, Fuji-Ortho LC, F-2000, and Z-100) were incubated with S. mutans GS-5 in culture media containing 5% sucrose (w/v). The media were changed daily for seven days, during which the pH and concentrations of fluoride and aluminum were determined. Furthermore, the concentrations of these ions and insoluble polysaccharide were determined in the biofilm formed at the end of the experimental period. The results showed that all the materials tested released fluoride. However, Vitremer released the highest amount of aluminum and was the most effective in reducing the acidogenicity of S. mutans biofilms. It also significantly affected both biofilm formation and composition. Thus, this study suggests that aluminum released by ionomeric materials may enhance the biological effects of fluoride.

  12. Effectiveness of silver diamine fluoride and sodium fluoride varnish in arresting dentin caries in Chinese pre-school children

    OpenAIRE

    Chu, CH; Lo, ECM; Lin, HC

    2002-01-01

    Untreated dental caries in Chinese pre-school children is common. This prospective controlled clinical trial investigated the effectiveness of topical fluoride applications in arresting dentin caries. Three hundred seventy-five children, aged 3-5 years, with carious upper anterior teeth were divided into five groups. Children in the first and second groups received annual applications of silver diamine fluoride solution (44,800 ppm F). Sodium fluoride varnish (22,600 ppm F) was applied every ...

  13. Exposure to Fluoride in Smelter Workers in a Primary Aluminum Industry in India

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    A Singh

    2013-04-01

    Full Text Available Background: Fluoride is used increasingly in a variety of industries in India. Emission of fluoride dust and fumes from the smelters of primary aluminum producing industries is dissipated in the work environment and poses occupational health hazards.Objective: To study the prevalence of health complaints and its association with fluoride level in body fluids of smelter workers in a primary aluminum producing industry.Methods: In an aluminum industry, health status of 462 smelter workers, 60 supervisors working in the smelter unit, 62 non-smelter workers (control group 1 and 30 administration staff (control group 2 were assessed between 2007 and 2009. Their health complaints were recorded and categorized into 4 groups: 1 gastro-intestinal complaints; 2 non-skeletal manifestations; 3 skeletal symptoms; and (4 respiratory problems. Fluoride level in body fluids, nails, and drinking water was tested by an ion selective electrode; hemoglobin level was tested using HemoCue.Results: The total complaints reported by study groups were significantly higher than the control groups. Smelter workers had a significantly (pConclusions: Industrial emission of fluoride is not the only important sources of fluoride exposure—consumption of substance with high levels of fluoride is another important route of entry of fluoride into the body. Measurement of hemoglobin provides a reliable indicator for monitoring the health status of employees at risk of fluorosis.

  14. Mechanochemical synthesis of low-fluorine doped aluminum hydroxide fluorides

    Science.gov (United States)

    Scalise, V.; Scholz, G.; Kemnitz, E.

    2016-11-01

    Different aluminum hydroxide fluorides with varying Al/F molar ratios from 1:1.5 up to 1:0.05 were successfully synthesized by mechanochemical reactions. The characterization of the products by XRD, 27Al and 19F MAS NMR, thermal analysis, nitrogen adsorption and zeta potential techniques allows a detailed understanding of the structure and surface properties of the products. Using γ-Al(OH)3 and β-AlF3·3H2O as OH- and F-sources, respectively, strongly disordered products were obtained with an Al: F molar ratio higher than 1:0.25. The fluorination degree has affected the amount of 4- and 5-fold coordinated Al sites, not present in the reactants. An evolution of the sub-coordinated Al-species has been detected also as a consequence of annealing processes. Obviously, these species affect the phase transition to alumina, by decreasing the transition temperature of the formation of α-Al2O3. Synthesis conditions (milling time, fluorination degree) play a crucial role for the product composition.

  15. Effect of sodium fluoride in maternal and offspring rats and its amelioration

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    Sneha Panchal

    2014-03-01

    Full Text Available High fluoride content is known to cause dental and skeletal abnormalities. In addition, present review indicates that sodium fluoride consumption caused increased number of r=esorptions and dead foetuses. Various skeletal anomalies such as wavy ribs, presence of 14th ribs, lacking 6th sternebrae and incompete ossification of skull occur. All these changes could be due to oxidative stress caused by fluoride consumption. Fluoride-induced changes could be successfully ameliorated by cotreatment with vitamins and calcium.

  16. Effect of sodium fluoride in maternal and offspring rats and its amelioration

    Institute of Scientific and Technical Information of China (English)

    SnehaPanchal; RamtejJ. Verma

    2014-01-01

    High fluoride content is known to cause dental and skeletal abnormalities. In addition, present review indicates that sodium fluoride consumption caused increased number of r=esorptions and dead foetuses. Various skeletal anomalies such as wavy ribs, presence of 14th ribs, lacking 6th sternebrae and incompete ossification of skull occur. All these changes could be due to oxidative stress caused by fluoride consumption. Fluoride-induced changes could be successfully ameliorated by cotreatment with vitamins and calcium.

  17. Role of Spirulina in mitigating hemato-toxicity in Swiss albino mice exposed to aluminum and aluminum fluoride.

    Science.gov (United States)

    Sharma, Shweta; Sharma, K P; Sharma, Subhasini

    2016-12-01

    Aluminum is ingested through foods, water, air, and even drugs. Its intake is potentiated further through foods and tea prepared in aluminum utensils and Al salt added in the drinking water for removal of suspended impurities and also fluoride in the affected areas. The ameliorating role of a blue green alga Spirulina is well documented to various pollutants in the animal models. We, therefore, examined its protective role (230 mg/kg body weight) on the hematology of male Swiss albino mice treated with aluminum (sub-acute = 78.4 mg/kg body weight for 7 days, sub-chronic = 7.8 mg/kg body weight for 90 days) and aluminum fluoride (sub-acute = 103 mg/kg body weight, sub-chronic = 21 mg/kg body weight), along with their recovery after 90 days of sub-chronic exposure. This study revealed significant reduction in the values of RBC (5-18 %), Hb (15-17 %), PCV (8-14 %), and platelets (26-36 %), and increase in WBC (54-124 %) in the treated mice, particularly after sub-acute exposure. Aluminum fluoride was comparatively more toxic than aluminum. Further, Spirulina supplement not only alleviated toxicity of test chemicals in Swiss albino mice but also led to their better recovery after withdrawal.

  18. Hydrogen storage in sodium aluminum hydride.

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    Ozolins, Vidvuds; Herberg, J.L. (Lawrence Livermore National Laboratories, Livermore, CA); McCarty, Kevin F.; Maxwell, Robert S. (Lawrence Livermore National Laboratories, Livermore, CA); Stumpf, Roland Rudolph; Majzoub, Eric H.

    2005-11-01

    Sodium aluminum hydride, NaAlH{sub 4}, has been studied for use as a hydrogen storage material. The effect of Ti, as a few mol. % dopant in the system to increase kinetics of hydrogen sorption, is studied with respect to changes in lattice structure of the crystal. No Ti substitution is found in the crystal lattice. Electronic structure calculations indicate that the NaAlH{sub 4} and Na{sub 3}AlH{sub 6} structures are complex-ionic hydrides with Na{sup +} cations and AlH{sub 4}{sup -} and AlH{sub 6}{sup 3-} anions, respectively. Compound formation studies indicate the primary Ti-compound formed when doping the material at 33 at. % is TiAl{sub 3} , and likely Ti-Al compounds at lower doping rates. A general study of sorption kinetics of NaAlH{sub 4}, when doped with a variety of Ti-halide compounds, indicates a uniform response with the kinetics similar for all dopants. NMR multiple quantum studies of solution-doped samples indicate solvent interaction with the doped alanate. Raman spectroscopy was used to study the lattice dynamics of NaAlH{sub 4}, and illustrated the molecular ionic nature of the lattice as a separation of vibrational modes between the AlH{sub 4}{sup -} anion-modes and lattice-modes. In-situ Raman measurements indicate a stable AlH{sub 4}{sup -} anion that is stable at the melting temperature of NaAlH{sub 4}, indicating that Ti-dopants must affect the Al-H bond strength.

  19. Effect of sodium fluoride and sodium nitroprouside on Cicer arietinum and Pisum sativum

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    Naba Kumar Mondal

    2016-07-01

    Full Text Available In present study, the individual and combine effect of sodium fluoride (NaF and sodium nitroprouside (SNP on germination and biochemical parameters (pigments, sugar, protein, amino acid, and phenol of Bengal gram (Cicer arietinum and peas (Pisum sativum has been studied. After three days of NaF treatment, reductions were observed in percentage of seed germination, root and shoot length, and pigment content with increasing concentration of NaF (1 to 4 mg L-1. Seedlings treated with SNP, both alone and in combination of NaF, showed enhancement in seed germination as well as other growth parameters. NaF-treated seedlings were found to accumulate more soluble sugars and phenols, which were further increased by SNP treatment thereby indicating a synergistic effect of the possible reasons for the ameliorative effects of SNP in seedlings of Pisum sativum growing under NaF stress. Results also demonstrated that SNP application did not show any improvement in both morpho-physiologically and biochemically under sodium fluoride stress condition.

  20. Erosion-inhibiting effect of sodium fluoride and titanium tetrafluoride treatment in vitro

    NARCIS (Netherlands)

    Rijkom, Hans van; Ruben, J.; Vieira, A.; Huysmans, M.C.; Truin, G-J.; Mulder, J.

    2003-01-01

    The prevention of dental erosion with fluoride is still largely unknown territory. It was the aim of this study to determine the erosion-inhibiting effect of topical neutral 1% sodium fluoride (NaF) application and an application of a 4% titanium tetrafluoride (TiF4) solution compared with no treatm

  1. Determination of Trace Iron in High Purity Sodium Fluoride by Graphite Furnace Atomic Absorption Spectrometry

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A method is described for the direct determination of iron in high purity sodium fluoride using graphite furnace atomic absorption spectrometry. Interferences caused by the matrix are investigated. It is shown that the ashing temperature can be increased to 1 400°C and matrix interferences eliminated, the sensi tivity of iron increased in 1.27 fold by the addition of nickel nitrate. The method is applied to the determina tion of iron in sodium fluoride and satisfactory results are obtained.

  2. Reactions of aluminum with uranium fluorides and oxyfluorides

    Energy Technology Data Exchange (ETDEWEB)

    Leitnaker, J.M.; Nichols, R.W.; Lankford, B.S. [Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States)

    1991-12-31

    Every 30 to 40 million operating hours a destructive reaction is observed in one of the {approximately}4000 large compressors that move UF{sub 6} through the gaseous diffusion plants. Despite its infrequency, such a reaction can be costly in terms of equipment and time. Laboratory experiments reveal that the presence of moderate pressures of UF{sub 6} actually cools heated aluminum, although thermodynamic calculations indicate the potential for a 3000-4000{degrees}C temperature rise. Within a narrow and rather low (<100 torr; 1 torr = 133.322 Pa) pressure range, however, the aluminum is seen to react with sufficient heat release to soften an alumina boat. Three things must occur in order for aluminum to react vigorously with either UF{sub 6} or UO{sub 2}F{sub 2}. 1. An initiating source of heat must be provided. In the compressors, this source can be friction, permitted by disruption of the balance of the large rotating part or by creep of the aluminum during a high-temperature treatment. In the absence of this heat source, compressors have operated for 40 years in UF{sub 6} without significant reaction. 2. The film protecting the aluminum must be breached. Melting (of UF{sub 5} at 620 K or aluminum at 930 K) can cause such a breach in laboratory experiments. In contrast, holding Al samples in UF{sub 6} at 870 K for several hours produces only moderate reaction. Rubbing in the cascade can undoubtedly breach the protective film. 3. Reaction products must not build up and smother the reaction. While uranium products tend to dissolve or dissipate in molten aluminum, AIF{sub 3} shows a remarkable tendency to surround and hence protect even molten aluminum. Hence the initial temperature rise must be rapid and sufficient to move reactants into a temperature region in which products are removed from the reaction site.

  3. Cytological reactions induced by sodium fluoride in Allium cepa root tip chromosomes

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, A.H.; Applegate, H.G.; Smith, J.D.

    1966-06-01

    The cytological effect of an aqueous sodium fluoride solution of lx10/sup -2/M was studied on onion root tip chromosomes. Root tip smears showed that this chemical agent was able to induce anaphase bridges and fragments. Tetraploid nuclei and multipolar anaphases were also observed.

  4. The Adsorption of Isobutyramide at the Mercury/Aqueous Sodium Fluoride Solution Interface

    Science.gov (United States)

    1989-05-01

    Sodium Fluoride Solution Interface by W.R. Fawcett and A.J. Motheo Prepared for Presentation at Electrochemical Society Meeting Los Angeles, CA May...ge Prepared for presentation at: Electrochemical Society Meeting, Los Angeles, CA, May 1989. A#J - 30 "W" The differential capacity of the electrode

  5. Fluoride

    Science.gov (United States)

    ... prescribed for children and adults whose homes have water that is not fluoridated (already has fluoride added). ... call your doctor immediately: unusual increase in saliva salty or soapy taste stomach pain upset stomach vomiting ...

  6. Synthesis of Renewable Energy Materials, Sodium Aluminum Hydride by Grignard Reagent of Al

    Directory of Open Access Journals (Sweden)

    Jun-qin Wang

    2015-01-01

    Full Text Available The research on hydrogen generation and application has attracted widespread attention around the world. This paper is to demonstrate that sodium aluminum hydride can be synthesized under simple and mild reaction condition. Being activated through organics, aluminum powder reacts with hydrogen and sodium hydride to produce sodium aluminum hydride under atmospheric pressure. The properties and composition of the sample were characterized by FTIR, XRD, SEM, and so forth. The results showed that the product through this synthesis method is sodium aluminum hydride, and it has higher purity, perfect crystal character, better stability, and good hydrogen storage property. The reaction mechanism is also discussed in detail.

  7. The characteristics of dissolution of fluoride and aluminum from brick tea

    Institute of Scientific and Technical Information of China (English)

    LIU Xiaojing; ZHENG Baoshan; WANG Binbin; WANG Mingshi

    2005-01-01

    Four experiments have been done on the influence of times of infusion, temperature, time and ratio of tea to water on the dissolving characteristics of fluoride and aluminum in brick tea. According to the results, the behaviors of F and Al which found their way into tea liquor were analyzed and the conclusions have been drawn: the dissolution of F and Al is not synchronous and after the elements find their way into tea liquor respectively, they will be reset to form complexes of F and Al.

  8. Benefits of a silica-based fluoride toothpaste containing o-cymen-5-ol, zinc chloride and sodium fluoride.

    Science.gov (United States)

    Newby, Craig S; Rowland, Joanna L; Lynch, Richard J M; Bradshaw, David J; Whitworth, Darren; Bosma, Mary Lynn

    2011-08-01

    Fluoride toothpastes in conjunction with tooth brushing are used to clean teeth, control plaque build-up and for anti-caries benefits. Toothpastes are designed with attractive flavours and appearances to encourage regular prolonged use to maximise these benefits. The incorporation of additional ingredients into toothpaste is a convenient way to provide supplementary protection that fits into people's everyday oral care routine. Such ingredients should not compromise the primary health benefits of toothpaste nor discourage its use. o-Cymen-5-ol and zinc chloride have been incorporated into a sodium fluoride (NaF)/silica toothpaste at 0.1%w/w and 0.6%w/w respectively to provide additional benefits. These include improved gingival health maintenance, in terms of the reduction of plaque, gingival index and bleeding, and an immediate and long lasting reduction in volatile sulfur compounds (VSCs) measured on breath. These benefits can be attributed to the antimicrobial and neutralisation actions of the toothpaste. The use of established fluoride models demonstrated no compromise in NaF bioavailability. The toothpaste was formulated without compromising product aesthetics. The combination of o-cymen-5-ol and zinc chloride in toothpaste gave superior maintenance of gingival health and reduction in malodour related VSCs without compromising the primary health benefits of the toothpaste or diminishing attributes preferred for the product's use.

  9. Controlled synthesis and formation mechanism of sodium yttrium fluoride nanotube arrays

    Institute of Scientific and Technical Information of China (English)

    TIAN Li; TAN Li; SUN Qiliang; XIANG Shaobin; XIAO Qiuguo; TANG Jianting; ZHU Guangshan

    2012-01-01

    Cubic and hexagonal sodium yttrium fluoride were successfully synthesized from yttrium nitrate,sodium fluoride and polyethanediol in propanetriol solvent under a facile hydrothermal route.By regulating the molar ratio of yttrium and fluoride,hydrothermal temperature and reaction time,the phase and shape of sodium yttrium fluoride were commendably controlled.The as-prepared products were characterized by X-ray diffraction (XRD),scanning electron microscopy (SEM) and energy dispersive X-ray spectrum (EDS) techniques.It was revealed that the hollow-structured Na(Y1.5Na0.5)F6 nanotubes self-assembled and arrayed orientedly to be bamboo raft-shaped.The formation of hexagonal Na(Y1.5Na0.5)F6 nanotube arrays was attributed to solid-liquid-solid process and Oswald ripening.This study provided a simple method to prepare hexagonal bamboo raft-shaped Na(Y1.5Na0.5)F6 on a large scale,which broadened their practical applications.

  10. Estimation of glycated hemoglobin sample in sodium fluoride vacutainer: A better option

    Directory of Open Access Journals (Sweden)

    Bhawna Singh

    2014-06-01

    Full Text Available Glycated hemoglobin (HbA1c nowadays used as a prognostic and diagnostic marker for glycaemic control in patients with diabetes mellitus. For estimation of HbA1c, preferred sample type is whole blood collected in vacutainer containing ethylenediaminetetraacetic acid (EDTA as anticoagulant. Sodium fluoride tubes can also be used as an alternative for estimation of HbA1c. Hence, by using fluoride vacutainer we can analyze both blood sugar and glycated hemoglobin. J Clin Exp Invest 2014; 5 (2: 336-338

  11. Ultraviolet optical properties of aluminum fluoride thin films deposited by atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Hennessy, John, E-mail: john.j.hennessy@jpl.nasa.gov; Jewell, April D.; Balasubramanian, Kunjithapatham; Nikzad, Shouleh [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109 (United States)

    2016-01-15

    Aluminum fluoride (AlF{sub 3}) is a low refractive index material with promising optical applications for ultraviolet (UV) wavelengths. An atomic layer deposition process using trimethylaluminum and anhydrous hydrogen fluoride has been developed for the deposition of AlF{sub 3} at substrate temperatures between 100 and 200 °C. This low temperature process has resulted in thin films with UV-optical properties that have been characterized by ellipsometric and reflection/transmission measurements at wavelengths down to 200 nm. The optical loss for 93 nm thick films deposited at 100 °C was measured to be less than 0.2% from visible wavelengths down to 200 nm, and additional microstructural characterization demonstrates that the films are amorphous with moderate tensile stress of 42–105 MPa as deposited on silicon substrates. X-ray photoelectron spectroscopy analysis shows no signature of residual aluminum oxide components making these films good candidates for a variety of applications at even shorter UV wavelengths.

  12. Phytotoxicity of sodium fluoride and uptake of fluoride in willow trees.

    Science.gov (United States)

    Clausen, Lauge Peter Westergaard; Karlson, Ulrich Gosewinkel; Trapp, Stefan

    2015-01-01

    The willow tree (Salix viminalis) toxicity test and a cress seed germination test (Lepidium sativum) were used to determine uptake of F and phytotoxicity of NaF. Concentrations in hydroponic solutions were 0-1000 mg F/L and 0-400 mg F/L in the preliminary and definitive test. A third test was done with soils collected from a fluoride-contaminated site at Fredericia, Denmark. The EC10, EC20 and EC50-values for inhibition of transpiration were determined to 38.0, 59.6 and 128.7 mg F/L, respectively. The toxicity test with soil showed strong inhibition for the sample with the highest fluoride concentration (405 mg free F per kg soil, 75 mg F per L soil solution). The seed germination and root elongation test with cress gave EC10, EC20 and EC50-values of 61.4, 105.0 and 262.8 mg F/L, respectively. At low external concentrations, fluoride was taken up more slowly than water and at high external concentrations at the same velocity. This indicates that an efflux pump becomes overloaded at concentrations above 210 mg F/L. Uptake kinetics were simulated with a non-linear mathematical model, and the Michaelis-Menten parameters were determined to half-saturation constant KM near 2 g F/L and maximum enzymatic removal rate vmax at 9 g/(kg d).

  13. Comparison of the antimicrobial efficacy of chlorhexidine, sodium fluoride, fluoride with essential oils, alum, green tea, and garlic with lime mouth rinses on cariogenic microbes

    OpenAIRE

    Thomas, Ann; Thakur, Sneha; Mhambrey, Sanjana

    2015-01-01

    Background: A number of natural mouth rinse formulations are being proposed as an alternative to the widely used chemical mouth rinses. Objective: To evaluate and compare the antimicrobial efficacy of chlorhexidine (0.2%), sodium fluoride (0.05%), fluoride with essential oils (0.05%), alum (0.02 M), green tea, and garlic with lime mouth rinses against Streptococcus mutans, lactobacilli, and Candida albicans. Materials and Methods: The three microbes were isolated from the saliva samples colle...

  14. Removal of fluoride from drinking water using aluminum hydroxide coated activated carbon prepared from bark of Morinda tinctoria

    Science.gov (United States)

    Amalraj, Augustine; Pius, Anitha

    2016-10-01

    The aim of this study is to design and develop a novel cost effective method for fluoride removal, applicable to rural areas of developing countries. Adsorption is widely considered as one of the appropriate technologies for water defluoridation. This study investigates the feasibility of using low-cost biomass based activated carbon from the bark of Morinda tinctoria coated with aluminum hydroxide (AHAC) for water defluoridation, at neutral pH range. Characterization of AHAC was done through IR, SEM with EDAX studies before and after fluoride treatment. The fluoride adsorption capacity of AHAC as a function of contact time, pH and initial fluoride concentration was investigated. The role of co-existing interfering ions also was studied. The isotherm and kinetic models were used to understand the nature of the fluoride adsorption onto AHAC. Freundlich isotherm and intra-particle diffusion were the best-fitting models for the adsorption of fluoride on AHAC. Fluoride adsorption kinetics well fitted with pseudo-second order model. The results showed excellent fluoride adsorption capacity was found to be 26.03 mg g-1 at neutral pH.

  15. Catalase and sodium fluoride mediated rehabilitation of enamel bleached with 37% hydrogen peroxide

    Directory of Open Access Journals (Sweden)

    Ruchi Thakur

    2015-01-01

    Full Text Available Background: Bleaching agents bring about a range of unwanted changes in the physical structure of enamel which needs to be restored qualitatively and timely. Catalase being an antioxidant ensures the effective removal of free radicals and improvement in fluoride mediated remineralization from the enamel microstructure which if retained may harm the integrity and affect the hardness of enamel. Materials and Methods: Thirty freshly extracted incisors were sectioned to 6 slabs which were divided into 5 groups: Group A, control; Group B, treatment with 37% hydrogen peroxide (HP; Group C, treatment with 37% HP and catalase, Group D, treatment with 37% HP and 5% sodium fluoride application, Group E, treatment with 37% HP followed by catalase and 5% sodium fluoride. Scanning electron microscope and microhardness analysis were done for all slabs. One-way ANOVA test was applied among different groups. Results: Vicker′s microhardness number (VHN of Group B and C was significantly lower. No significant difference between VHN of Group B and C. VHN of Group D was significantly higher than Group A, B, and C; but significantly lower than Group E. VHN of Group E was significantly higher than any other experimental group. One-way ANOVA revealed a highly significant P value (P = 0.0001 and so Tukey′s post-hoc Test for the group comparisons was employed. Conclusion: Subsequent treatment of bleached enamel with catalase and fluoride varnish separately results in repairing and significantly increasing the microhardness.

  16. Bioactivity of Sodium Free Fluoride Containing Glasses and Glass-Ceramics

    Directory of Open Access Journals (Sweden)

    Xiaojing Chen

    2014-07-01

    Full Text Available The bioactivity of a series of fluoride-containing sodium-free calcium and strontium phosphosilicate glasses has been tested in vitro. Glasses with high fluoride content were partially crystallised to apatite and other fluoride-containing phases. The bioactivity study was carried out in Tris and SBF buffers, and apatite formation was monitored by XRD, FTIR and solid state NMR. Ion release in solutions has been measured using ICP-OES and fluoride-ion selective electrode. The results show that glasses with low amounts of fluoride that were initially amorphous degraded rapidly in Tris buffer and formed apatite as early as 3 h after immersion. The apatite was identified as fluorapatite by 19F MAS-NMR after 6 h of immersion. Glass degradation and apatite formation was significantly slower in SBF solution compared to Tris. On immersion of the partially crystallised glasses, the fraction of apatite increased at 3 h compared to the amount of apatite prior to the treatment. Thus, partial crystallisation of the glasses has not affected bioactivity significantly. Fast dissolution of the amorphous phase was also indicated. There was no difference in kinetics between Tris and SBF studies when the glass was partially crystallised to apatite before immersion. Two different mechanisms of apatite formation for amorphous or partially crystallised glasses are discussed.

  17. Quantitative Structure—Activity Relationships in the Lithium and Sodium Affinities of n—Alkyl Fluorides

    Institute of Scientific and Technical Information of China (English)

    KeChunZHANG; JianMiaoFAN; 等

    2002-01-01

    B3L YP/6-31+g(d,p)method was used to calculate the lithium and sodium affinities of n-alkyl fluoride. These affinities were found to obey the Holmes relationship, i.e.they correlate linearly with the quotient n/(n+1), where n is the number of carbon atoms in the alkyl chain. From the correlation the limiting values of lithium and sodium affinities for very long alkyl chain were predicted to be-153.3kJ/mol and -108.4kJ/mol,respectively.

  18. Quantitative Structure-Activity Relationships in the Lithium and Sodium Affinities of n-Alkyl Fluorides

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    B3LYP/6-31+g (d, p) method was used to calculate the lithium and sodium affinities of n-alkyl fluoride. These affinities were found to obey the Holmes relationship, i.e. they correlate linearly with the quotient n/(n+1), where n is the number of carbon atoms in the alkyl chain. From the correlation the limiting values of lithium and sodium affinities for very long alkyl chain were predicted to be -153.3 kJ/mol and -108.4 kJ/mol, respectively.

  19. Growth, spectral, structural and mechanical properties of struvite crystal grown in presence of sodium fluoride

    Indian Academy of Sciences (India)

    K Suguna; M Thenmozhi; C Sekar

    2012-08-01

    Struvite or magnesium ammonium phosphate hexahydrate (MAP) is one of the components of urinary stone. Struvite stones are commonly found in women. It forms in human beings as a result of urinary tract infection with urea splitting organisms. These stones can grow rapidly forming “staghorn-calculi”, which is a painful urological disorder. Therefore, it is of prime importance to study the growth and inhibition of struvite crystals. The growth inhibition effect of struvite crystals in sodium metasilicate (SMS) gel in the presence of sodium fluoride has been carried out. Crystals obtained have been analysed by powder and single crystal XRD, SEM–EDX, FTIR and TG–DTA. The results show that the presence of fluoride significantly affects struvite crystal growth and the characteristics of the crystallites produced. The mechanical property of the grown crystals has been investigated by Vickers microhardness testing. Work hardening coefficient was found to be >1.6 for both pure and doped samples which suggests that the crystal belongs to the family of soft material. Presence of sodium fluoride further softened the crystal.

  20. Toxicity assessment of sodium fluoride in Drosophila melanogaster after chronic sub-lethal exposure.

    Science.gov (United States)

    Dutta, Moumita; Rajak, Prem; Khatun, Salma; Roy, Sumedha

    2017-01-01

    Sodium fluoride (NaF), one of the most frequently used fluoride compound is composed of Na(+) and F(-). Apart from its use in water fluoridation, NaF also acts as a major component for different dental products like toothpastes, gels and mouth rinses etc. The present study was carried out to explore the toxic impact of chronic NaF exposure on a non-target organism, Drosophila melanogaster. The larvae exposed to different concentrations of NaF through food showed a significant increase in HSP70 expression both qualitatively and quantitatively. The altered tail length and tail intensity in Comet assay validate the increased DNA damage in treated larvae. The activity of AChE, oxidative stress marker enzymes, phase I and phase II detoxifying enzymes were found to be significantly inhibited in the treated larvae when compared to control though there was no evidence of dose dependent change in each case. The alterations in the mentioned parameters can be due to increased body Fluoride ion (F(-)) concentration since the analysis with ion electrode analyzer revealed that F(-) concentration increased significantly with NaF treatment. Hence, the results suggest that D. melanogaster manifest prominent toxic response when subjected to chronic exposure to sub-lethal NaF concentrations.

  1. An automated method for preparation of [{sup 18}F]sodium fluoride for injection, USP to address the technetium-99m isotope shortage

    Energy Technology Data Exchange (ETDEWEB)

    Hockley, Brian G. [University of Michigan School of Medicine, Ann Arbor, MI (United States); Scott, Peter J.H. [University of Michigan School of Medicine, Ann Arbor, MI (United States)], E-mail: pjhscott@umich.edu

    2010-01-15

    The worldwide shortage of technetium-99m has created an immediate and urgent need for access to [{sup 18}F]sodium fluoride for PET imaging of bone metastasis. In order to facilitate global availability of [{sup 18}F]sodium fluoride for diagnostic nuclear medicine imaging procedures, a straightforward method for rapid production of [{sup 18}F]sodium fluoride for injection, USP, using a modified GE Tracerlab FX-FN is presented.

  2. Effect of xylitol, sodium fluoride and triclosan containing mouth rinse on Streptococcus mutans

    Directory of Open Access Journals (Sweden)

    Priya Subramaniam

    2011-01-01

    Full Text Available Introduction : Prevention of dental caries is one of the main strategies in contemporary pediatric dental practice. Mouth rinses are widely used as an adjunct to maintain oral hygiene. It is important for these products to be effective and safe for regular use in children. Objective : The aim of the study was to investigate the efficacy of a newly introduced xylitol, sodium fluoride and triclosan containing mouth rinse in reducing levels of plaque Streptococcus mutans and to compare it with that of a 0.12% chlorhexidine mouth rinse. Materials and Methods : Thirty children were randomly divided into two groups of 15 children each. Group I (study group was given a mouth rinse containing xylitol (5%, sodium fluoride (0.05% and triclosan (0.03% and Group II (control group was given a chlorhexidine (0.12% mouth rinse. Both mouth rinses were alcohol free. Mouth rinsing was carried out twice daily, half an hour after breakfast and half an hour following dinner, for a period of 21 days under the supervision of the investigator. Results: In both groups, there was a significant reduction in the mean S. mutans count at the end of 21 days (P < 0.001. No significant difference was observed between the two mouth rinses. Conclusion: The use of a low fluoride-xylitol based mouth rinse appears to be a suitable choice for regular use in children.

  3. Effect of silymarin on sodium fluoride-induced toxicity and oxidative stress in rat cardiac tissues

    Directory of Open Access Journals (Sweden)

    Seyed M. Nabavi

    2012-12-01

    Full Text Available This study aim to evaluate the protective effect of silymarin on sodium fluoride-induced oxidative stress in rat cardiac tissues. Animals were pretreated with silymarin at 20 and 10 mg/kg prior to sodium fluoride consumption (600 ppm through drinking water. Vitamin C at 10 mg/kg was used as standard antioxidant. There was a significant increase in thiobarbituric acid reactive substances level (59.36 ± 2.19 nmol MDA eq/g tissue along with a decrease in antioxidant enzymes activity (64.27 ± 1.98 U/g tissue for superoxide dismutase activity and 29.17 ± 1.01 µmol/min/mg protein for catalase activity and reduced glutathione level (3.8 ± 0.15 µg/mg protein in the tissues homogenates of the sodium fluoride-intoxicated rats. Silymarin administration to animals before sodium fluoride consumption modified the levels of biochemical parameters.Este estudo objetiva avaliar o efeito protetor da silimarina em fluoreto de sódio induzida por estresse oxidativo em tecido cardíaco de ratos. Os animais foram pré-tratados com silimarina a 20 e 10 mg/kg antes do consumo de fluoreto de sódio (600 ppm através da água de beber. A vitamina C a 10 mg/kg foi utilizada como antioxidante padrão. Houve um aumento significativo no nível de substâncias tiobarbitúrico reativo de ácido (59,36 ± 2.19 nmol MDA eq/g tecido, juntamente com uma diminuição da atividade de enzimas antioxidantes (64,27 ± 1,98 U/g tecido para a atividade de superóxido dismutase e 29,7 ± 1,01 mmol/min/mg de proteína para a atividade da catalase e nível de glutationa reduzida (3,8 ± 0,15 mg/mg de proteína nos homogeneizados de tecidos dos fluoreto de sódio-intoxicados ratos. Administração de silimarina a animais, antes do consumo de fluoreto de sódio modifou os níveis de parâmetros bioquímicos.

  4. Exposure to sodium fluoride produces signs of apoptosis in rat leukocytes.

    Science.gov (United States)

    Gutiérrez-Salinas, José; Morales-González, José A; Madrigal-Santillán, Eduardo; Esquivel-Soto, Jaime; Esquivel-Chirino, César; González-Rubio, Manuel García-Luna Y; Suástegui-Domínguez, Sigrit; Valadez-Vega, Carmen

    2010-09-27

    Fluoride is naturally present in the earth's crust and can be found in rocks, coal, and clay; thus, it can be found in small quantities in water, air, plants, and animals. Therefore, humans are exposed to fluoride through food, drinking water, and in the air they breathe. Flouride is essential to maintain bone strength and to protect against dental decay, but if it is absorbed too frequently, it can cause tooth decay, osteoporosis, and damage to kidneys, bones, nerves, and muscles. Therefore, the present work was aimed at determining the effect of intake of sodium fluoride (NaF) as an apoptosis inducer in leukocytes of rats treated for eight weeks with 1 or 50 parts per million (ppm) NaF. Expression of p53, bcl-2, and caspade-3 were used as apoptotic and general metabolism indicators of leukocyte-like indicators of the (INT) oxidation system. Male rats were exposed to NaF (1 and 500 ppm) for eight weeks, and then sacrificed weekly to obtain blood samples. Expression of p53, bcl-2, and caspase-3 were determined in leukocytes by Western blot, and general metabolism of leukocytes was analyzed with a commercial kit. We found changes in the expression of the proteins described, especially when the animals received 50 ppm of NaF. These results indicate that NaF intoxication can be an apoptosis inducer in rat leukocytes treated with the compound for eight weeks.

  5. Exposure to Sodium Fluoride Produces Signs of Apoptosis in Rat Leukocytes

    Directory of Open Access Journals (Sweden)

    Sigrit Suástegui-Domínguez

    2010-09-01

    Full Text Available Fluoride is naturally present in the earth's crust and can be found in rocks, coal, and clay; thus, it can be found in small quantities in water, air, plants, and animals. Therefore, humans are exposed to fluoride through food, drinking water, and in the air they breathe. Flouride is essential to maintain bone strength and to protect against dental decay, but if it is absorbed too frequently, it can cause tooth decay, osteoporosis, and damage to kidneys, bones, nerves, and muscles. Therefore, the present work was aimed at determining the effect of intake of sodium fluoride (NaF as an apoptosis inducer in leukocytes of rats treated for eight weeks with 1 or 50 parts per million (ppm NaF. Expression of p53, bcl-2, and caspade-3 were used as apoptotic and general metabolism indicators of leukocyte-like indicators of the (INT oxidation system. Male rats were exposed to NaF (1 and 500 ppm for eight weeks, and then sacrificed weekly to obtain blood samples. Expression of p53, bcl-2, and caspase-3 were determined in leukocytes by Western blot, and general metabolism of leukocytes was analyzed with a commercial kit. We found changes in the expression of the proteins described, especially when the animals received 50 ppm of NaF. These results indicate that NaF intoxication can be an apoptosis inducer in rat leukocytes treated with the compound for eight weeks.

  6. The effect of sodium fluoride on the stability of cyanide in postmortem blood samples from fire victims.

    Science.gov (United States)

    McAllister, J L; Roby, R J; Levine, Barry; Purser, David

    2011-06-15

    Assigning a level of significance to cyanide concentrations found in the blood of fire victims is often hampered by the fact that cyanide is inherently unstable in cadavers and in stored blood samples. A few researchers have proposed that sodium fluoride can be used to minimize the instability of cyanide in blood samples; however, controlled studies have not been performed to support validation of this hypothesis. To test the sodium fluoride hypothesis, both treated and control blood samples from 14 autopsied fire victims were tested over a 25-30 day period. A 2% concentration of sodium fluoride was added to the blood samples at the start of testing and the samples were refrigerated between testing intervals. Cyanide concentrations in the treated and control samples were measured between 9 and 11 days post treatment and between 25 and 30 days post treatment. A statistically significant difference was not present between blood cyanide concentrations in treated and control samples between 9 and 11 days. During this time period, although there were small statistically significant increases in both treated and untreated samples the fluctuations were minor. Since the treated and control samples did not exhibit instability between 9 and 11 days, it is not surprising that the sodium fluoride appeared to have no effect. However, a statistically significant difference between blood cyanide concentrations in treated and control samples was observed between 25 and 30 days. Those samples treated with sodium fluoride showed a reduction in blood cyanide variability with virtually no overall change, over a 25-30 day period when compared to control samples, while unconditioned samples showed a significant, average increase of 35%. Based on the findings of this study, it is recommended that 2% sodium fluoride be added to blood samples obtained from fire victims to reduce cyanide instability due to bacteriological activity.

  7. Aluminum chloride for accelerating hydrogen generation from sodium borohydride

    Science.gov (United States)

    Demirci, U. B.; Akdim, O.; Miele, P.

    The present research paper reports preliminary results about the utilization of anhydrous aluminum chloride (AlCl 3) for accelerating hydrogen generation through hydrolysis of aqueous solution of sodium borohydride (NaBH 4) at 80 °C. To the best of our knowledge, AlCl 3 has never been considered for that reaction although many transition metal salts had already been assessed. AlCl 3 reactivity was compared to those of AlCl 3·6H 2O, AlF 3, CoCl 2, RuCl 3 and NiCl 2. With AlCl 3 and a NaBH 4 solution having a gravimetric hydrogen storage capacity (GHSC) of 2.9 wt.%, almost 100% hydrogen was generated in few seconds, i.e., with a hydrogen generation rate (HGR) of 354 L min -1 g -1(Al). This HGR is one of the highest rates ever reported. Higher HGRs were obtained by mixing AlCl 3 with CoCl2, RuCl 3 or NiCl 2. For example, the system RuCl 3:AlCl 3 (50:50 mass proportion) showed a HGR > 1000 L min -1 g -1(Ru:Al). The hydrolysis by-products (once dried) were identified (by XRD, IR and elemental analysis) as being Al(OH) 3, NaCl and Na 2B(OH) 4Cl and it was observed that even in situ formed Al(OH) 3 has catalytic abilities with HGRs of 5 L min -1 g -1(Al). All of these preliminary results are discussed, which concludes that AlCl 3 has a potential as accelerator for single-use NaBH 4-based storage system.

  8. Efficacy of 1% sodium fluoride as a preservative in urine samples containing glucose and Candida albicans.

    Science.gov (United States)

    Lough, P S; Fehn, R

    1993-03-01

    Whether urine samples used in forensic science DUI testing can be compromised by endogenous ethanol production is a recurrent and yet unresolved issue. This study first assessed unpreserved urine samples that were collected, processed, and analyzed repeatedly over 13 to 41 days using a standard gas chromatographic procedure for ethanol analysis. Despite extensive microbial growth, ethanol was not detected in any test sample. The extent of ethanol production in samples supplemented with glucose, Candida albicans, or both was determined to evaluate the potential for ethanol production in urine samples associated with pathological conditions such as urinary tract yeast infections and diabetes mellitus. Ethanol production under each of the above treatment conditions was assessed in the presence and absence of 1% sodium fluoride as a microbial suppressant. Mean ethanol concentrations were determined for unpreserved samples containing urine only (0.003 +/- 0.005 g%), urine plus yeast (0.006 +/- 0.009 g%) and urine plus glucose (0.067 +/- 0.070 g%). Unpreserved samples supplemented with both yeast and glucose attained mean ethanol concentrations of 0.164 +/- 0.057 g% (P urine samples indicates that false DUI convictions due to endogenous ethanol production are very unlikely. And while endogenous ethanol production is possible in the presence of both glucose and contaminating C. albicans, 1% sodium fluoride completely eliminated microbial fermentation.

  9. Delayed sodium (18)F-fluoride PET/CT imaging does not improve quantification of vascular calcification metabolism

    DEFF Research Database (Denmark)

    Blomberg, Björn Alexander; Thomassen, Anders; Takx, Richard A P;

    2014-01-01

    This study aimed to determine if delayed sodium (18)F-fluoride (Na(18)F) PET/CT imaging improves quantification of vascular calcification metabolism. Blood-pool activity can disturb the arterial Na(18)F signal. With time, blood-pool activity declines. Therefore, delayed imaging can potentially...... improve quantification of vascular calcification metabolism....

  10. Parenteral monofluorophosphate (MFP) is a more potent inducer of enamel fluorotic defects in neonatal hamster molars than sodium fluoride

    NARCIS (Netherlands)

    Lyaruu, D.M.; Schoonderwoerd, M.; Tio, D.; Tse, C.; Bervoets, T.J.; Denbesten, P.; Bronckers, A.L.J.J.

    2014-01-01

    Supra-optimal intake of sodium fluoride (NaF) during early childhood results in formation of irreversible enamel defects. Monofluorophosphate (MFP) was considered as less toxic than NaF but equally cariostatic. We compared the potency of MFP and NaF to induce pre-eruptive sub-ameloblastic cysts and

  11. Retention of long-term interim restorations with sodium fluoride enriched interim cement

    Science.gov (United States)

    Strash, Carolyn

    Purpose: Interim fixed dental prostheses, or "provisional restorations", are fabricated to restore teeth when definitive prostheses are made indirectly. Patients undergoing extensive prosthodontic treatment frequently require provisionalization for several months or years. The ideal interim cement would retain the restoration for as long as needed and still allow for ease of removal. It would also avoid recurrent caries by preventing demineralization of tooth structure. This study aims to determine if adding sodium fluoride varnish to interim cement may assist in the retention of interim restorations. Materials and methods: stainless steel dies representing a crown preparation were fabricated. Provisional crowns were milled for the dies using CAD/CAM technology. Crowns were provisionally cemented onto the dies using TempBond NE and NexTemp provisional cements as well as a mixture of TempBond NE and Duraphat fluoride varnish. Samples were stored for 24h then tested or thermocycled for 2500 or 5000 cycles before being tested. Retentive strength of each cement was recorded using a universal testing machine. Results: TempBond NE and NexTemp cements performed similarly when tested after 24h. The addition of Duraphat significantly decreased the retention when added to TempBond NE. NexTemp cement had high variability in retention over all tested time periods. Thermocycling for 2500 and 5000 cycles significantly decreased the retention of all cements. Conclusions: The addition of Duraphat fluoride varnish significantly decreased the retention of TempBond NE and is therefore not recommended for clinical use. Thermocycling significantly reduced the retention of TempBond NE and NexTemp. This may suggest that use of these cements for three months, as simulated in this study, is not recommended.

  12. Rich detector with a sodium fluoride radiator: /K identification up to 3 GeV/c

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, R.; Guyonnet, J.L.; Giomataris, Y.; Petroff, P.; Seguinot, J.; Tocqueville, J.; Ypsilantis, T.

    1988-12-15

    The use of a single crystal of sodium fluoride (NaF) as a Cherenkov radiator has been investigated. Its transparency has been measured and found to be good for photon energies below 9.6 eV. Data on its index of refraction are well fitted to a single-pole Sellmeier resonance formula. These data allow a realistic Monte Carlo simulation of a proximity-focused ring imaging Cherenkov (RICH) system. The photon detector is a multiwire proportional chamber (MWPC) with pad readout. The photosensitive gases considered are tetrakis(dimethylamine)ethylene (TMAE) and triethylamine (TEA). The simulation shows that a system having 10 cm radial thickness and 12% of a radiation length of material would identify pions and kaons below 3 GeV/c momentum. The pad dimensions required are about 5 mm x 5 mm.

  13. Comparative evaluation of 2% sodium fluoride iontophoresis and other cavity liners beneath silver amalgam restorations

    Directory of Open Access Journals (Sweden)

    Gupta M

    2010-06-01

    Full Text Available Background: This study was designed to compare 2% sodium fluoride (NaF iontophoresis with other cavity liners. Materials and Methods: This study was carried out in 30 patients in the age group 10-14 years with bilateral carious permanent first molars. The study evaluated the use of 2% NaF iontophoresis as a cavity liner and also compared its desensitizing effect with varnish and an adhesive bonded liner. Sensitivity gradings were done on a subjective verbal rating scale. Results: All the liner treatments decreased the sensitivity following liner application. However, decrease of sensitivity in the case of 2% NaF iontophoresis was more compared with that of varnish and adhesive bonded liner. The results were statistically significant. Conclusions: It was found that 2% NaF iontophoresis was more effective in reducing the postoperative sensitivity compared with that of varnish and scotchbond multipurpose.

  14. Bones and Crohn's: No benefit of adding sodium fluoride oribandronate to calcium and vitamin D

    Institute of Scientific and Technical Information of China (English)

    Jochen Klaus; Max Reinshagen; Katharina Herdt; Christoph Schr(o)ter; Guido Adler; Georg BT von Boyen; Christian von Tirpitz

    2011-01-01

    AIM: To compare the effect of calcium and cholecalciferol alone and along with additional sodium fluoride or ibandronate on bone mineral density (BMD) and fractures in patients with Crohn's disease (CD).METHODS: Patients (n =148) with reduced BMD (T-score< -1) were randomized to receive cholecalciferol (1000 IU) and calcium citrate (800 mg) daily alone(group A, n =32) or along with additional sodium fluoride (25 mg bid ) (group B, n = 62) or additional ibandronate (1 mg iv/3-monthly) (group C, n = 54). Dual energy X-ray absorptiometry of the lumbar spine (L1-L4) and proximal right femurand X-rays of the spine were performed at baseline and after 1.0, 2.25 and 3.5 years. Fracture-assessment included visual reading of X-rays and quantitative morphometry of vertebral bodies (T4-L4).RESULTS: One hundred and twenty three (83.1%) patients completed the first year for intention-to-treat (ITT) analysis. Ninety two (62.2%) patients completed thesecond year and 71 (47.8%) the third year available for per-protocol (PP) analysis. With a significant increase in T-score of the lumbar spine by +0.28 ± 0.35 [95%confidence interval (CI): 0.162-0.460, P < 0.01], +0.33 ± 0.49 (95% CI: 0.109-0.558, P < 0.01), +0.43 ± 0.47 (95% CI: 0.147-0.708, P < 0.01) in group A, +0.22 ±0.33 (95% CI: 0.125-0.321, P < 0.01); +0.47 ± 0.60 (95% CI: 0.262-0.676, P < 0.01), +0.51 ± 0.44 (95%CI: 0.338-0.682, P < 0.01) in group B and +0.22 ±0.38 (95% CI: 0.111-0.329, P < 0.01), +0.36 ± 0.53(95% CI: 0.147-0.578, P < 0.01), +0.41 ± 0.48 (95%CI: 0.238-0.576, P < 0.01) in group C, respectively, duringthe 1.0, 2.25 and 3.5 year periods (PP analysis), no treatment regimen was superior in any in- or betweengroup analyses. In the ITT analysis, similar results in allin- and between-group analyses with a significant ingroup but non-significant between-group increase in T-score of the lumbar spine by 0.38 ± 0.46 (group A,P < 0.01), 0.37 ± 0.50 (group B, P < 0.01) and 0.35 ±0.49 (group C, P < 0.01) was

  15. Formation of color centers and light scattering structures by femtosecond laser pulses in sodium fluoride

    Science.gov (United States)

    Bryukvina, L. I.; Pestryakov, E. V.; Kirpichnikov, A. V.; Martynovich, E. F.

    2014-11-01

    Modification of sodium fluoride crystal lattice by means of femtosecond laser pulses with λmax=800 nm, energy 0.5 mJ, duration 30 fs and repetition rate 1 kHz has been considered in the paper. Effective formation of simple and complex aggregate color centers and light scattering nanodefects in the channel of a laser beam in NaF crystal have been shown for the first time. Dependences of color centers concentration on the distance between the channel center and its periphery and along the channel have been presented. Influence of external focusing on color centers creation has been revealed. Explanations of the observed phenomena have been presented on the basis of nonlinear processes taking place under the effect of high-intensity femtosecond pulses.

  16. Allergy caused by sodium fluoride glycerin: A case report%氟化钠甘油过敏1例

    Institute of Scientific and Technical Information of China (English)

    马继红

    2012-01-01

    In recent years, though more and more ulcerations of oral mucosa caused by allergy to drug occurred clinically, allergy to sodium fluoride glycerin is extremely rare. A case of allergy to sodium fluoride glycerin occurred in Qianfoshan Campus Hospital of Shandong University. After treatment by sodium fluoride glycerin, there was mucosal edema, a large number of red miliary granules in buccal and palatal mucosa. After 3 hours, there were swallowing difficulties, but no breathing difficulties. Next day large ulcers of oral mucosa developed. The patient was cured 7 days after treatment. Fluoride-sensitive test result was positive.%近年来药物过敏引起的口腔黏膜溃疡越来越多,但氟化钠甘油过敏引起的溃疡却极少见.山东大学千佛山校区医院遇到氟化钠甘油过敏1例,氟化钠甘油治疗后患者口腔黏膜充血水肿明显,颊、腭黏膜有大量红色粟粒状颗粒,3h后出现吞咽困难,但无呼吸困难,次日出现口腔黏膜大面积溃疡.治疗7d后患者痊愈,氟化钠敏感试验结果为阳性.

  17. THE EFFECT OF FLUORIDE ON THE EFFECTIVENESS OF CONVENTIONAL COAGULATION/FLOCCULATION/SEDIMENTATION USING ALUMINUM SULFATE

    Science.gov (United States)

    The Safe Drinking Water Act states that no drinking water facility is reuqired to fluoridate their water, however, any facility fluoridating their water is bound by the Maximum contaminant Level (MCL) of 4 mg/L. A survey of 600 large water utilities was conducted in conjunction w...

  18. Continuous measurement of peak hydrogen fluoride exposures in aluminum smelter potrooms: instrument development and in-plant evaluation.

    Science.gov (United States)

    Dando, Neal; Xu, Weizong; Peace, Jon Nathaniel

    2008-02-01

    The aluminum smelting process continuously evolves both sulfur dioxide (SO2) and hydrogen fluoride (HF) gases. The vast majority of these evolved gases are captured by local exhaust ventilation systems and transported to fume treatment centers. Any gas escaping the ventilation systems could create the potential for workplace exposures. Currently, there are no commercially available sensors that are capable of selectively measuring peak concentrations (< 10 sec) of HF in the presence of SO2. This measurement capability is critical for facilitating a better understanding of the etiology of respiratory health effects. This article presents the development and in-plant testing of a portable, tunable diode-based HF sensor that shows equivalent or improved performance relative to NIOSH Method 7902 and is capable of measuring short-term personal peak HF exposure potentials in operating aluminum smelters.

  19. Simulation of thermal and sodium expansion stress in aluminum reduction cells

    Institute of Scientific and Technical Information of China (English)

    LI Jie; WU Yu-yun; LAI Yan-qing; LIU Wei; WANG Zhi-gang; LIU Jie; LIU Ye-xiang

    2008-01-01

    Two finite element(FE) models were built up for analysis of stress field in the lining of aluminum electrolysis cells. Distribution of sodium concentration in cathode carbon blocks was calculated by one FE model of a cathode block. Thermal stress field was calculated by the other slice model of the cell at the end of the heating-up. Then stresses coupling thermal and sodium expansion were considered after 30 d start-up. The results indicate that sodium penetrates to the bottom of the cathode block after 30 d start-up. The semi-graphitic carbon block has the largest stress at the thermal stage. After 30 d start-up the anthracitic carbon has the greatest sodium expansion stress and the graphitized carbon has the lowest sodium expansion stress. Sodium penetration can cause larger deformation and stress in the cathode carbon block than thermal expansion.

  20. Effects of fluoride emissions from a modern primary aluminum smelter on a local population of white-tailed deer (Odocoileus virginianus)

    Energy Technology Data Exchange (ETDEWEB)

    Suttie, J.S.; Dickie, R.; Clay, A.B.; Nielsen, P.; Mahan, W.E.; Baumann, D.P.; Hamilton, R.J.

    1987-01-01

    The influence of fluoride emissions from a modern aluminum smelter on concentrations of skeletal fluoride and dental fluorosis in a resident population of white-tailed deer was studied. The smelter was located on Mount Holly Plantation in South Carolina, and concentrations of skeletal fluoride in the deer collected at Mount Holly increased approximately five-fold 3 yr after the operation began. Increases in skeletal fluoride of less than two-fold were observed in deer obtained from Medway Plantation which has its nearest boundary 1.6 km from the smelter site. No dental fluorosis was observed in deer collected at Medway Plantation, but mild dental fluorosis was observed in a significant number of deer collected at Mount Holly Plantation. The dental fluorosis that was observed was not associated with incisor wear or with fluoride-induced molar wear. Osteofluorosis of mandibles or metacarpals was not observed in any of the deer obtained from either plantation. The data obtained from this study indicated that the presence of a modern aluminum smelter caused a detectable increase in concentration of skeletal fluoride in the resident population of white-tailed deer, but that no adverse health effects were seen.

  1. Micromolar sodium fluoride mediates anti-osteoclastogenesis in Porphyromonas gingivalis-induced alveolar bone loss

    Institute of Scientific and Technical Information of China (English)

    Ujjal K Bhawal; Nobushiro Hamada; Ikuo Nasu; Hirohisa Arakawa; Koh Shibutani; Hye-Jin Lee; Kazumune Arikawa; Michiharu Shimosaka; Masatoshi Suzuki; Toshizo Toyama; Takenori Sato; Ryota Kawamata; Chieko Taguchi

    2015-01-01

    Osteoclasts are bone-specific multinucleated cells generated by the differentiation of monocyte/macrophage lineage precursors. Regulation of osteoclast differentiation is considered an effective therapeutic approach to the treatment of bone-lytic diseases. Periodontitis is an inflammatory disease characterized by extensive bone resorption. In this study, we investigated the effects of sodium fluoride (NaF) on osteoclastogenesis induced by Porphyromonas gingivalis, an important colonizer of the oral cavity that has been implicated in periodontitis. NaF strongly inhibited the P. gingivalis-induced alveolar bone loss. That effect was accompanied by decreased levels of cathepsin K, interleukin (IL)-1b, matrix metalloproteinase 9 (MMP9), and tartrate-resistant acid phosphatase, which were up-regulated during P. gingivalis-induced osteoclastogenesis. Consistent with the in vivo anti-osteoclastogenic effect, NaF inhibited osteoclast formation caused by the differentiation factor RANKL (receptor activator of nuclear factor kB ligand) and macrophage colony-stimulating factor (M-CSF). The RANKL-stimulated induction of the transcription factor nuclear factor of activated T cells (NFAT) c1 was also abrogated by NaF. Taken together, our data demonstrate that NaF inhibits RANKL-induced osteoclastogenesis by reducing the induction of NFATc1, ultimately leading to the suppressed expression of cathepsin K and MMP9. The in vivo effect of NaF on the inhibition of P. gingivalis-induced osteoclastogenesis strengthens the potential usefulness of NaF for treating periodontal diseases.

  2. Clinical performance of topical sodium fluoride when supplementing carbamide peroxide at-home bleaching gel.

    Science.gov (United States)

    Barcellos, Daphne Camara; Batista, Graziela Ribeiro; da Silva, Melissa Aline; Pleffken, Patricia Rondon; Valera, Marcia Carneiro

    2015-01-01

    This clinical study evaluated the use of 0.11% topical sodium fluoride (SF) desensitizing agent to treat tooth sensitivity during a nightguard tooth whitening procedure. Thirty-two subjects bleached their teeth with 10% carbamide peroxide (CP) gel using an at-home bleaching technique with custom trays. During bleaching treatment, subjects were divided into 2 groups (n = 16). The subjects in Group 1 received a topical gel containing 0.11% SF; the subjects in Group 2 received a placebo gel (PG). Each subject was instructed to place the gel in his/her bleaching tray for 30 min every day following bleaching treatment. Results showed the use of SF did not affect the whitening efficacy of the 10% CP gel. Subjects who received the PG had significantly higher tooth sensitivity when compared with subjects who received SF (P < 0.00). The use of daily 0.11% SF after 10% CP bleaching gel reduced tooth sensitivity during the bleaching treatment.

  3. Comparison of nano-hydroxyapatite and sodium fluoride mouthrinse for remineralization of incipient carious lesions.

    Directory of Open Access Journals (Sweden)

    Roza Haghgoo

    2014-08-01

    Full Text Available Dental caries is an infectious disease that can be prevented in several ways. The aim of this study was to compare the efficacy of sodium fluoride mouthrinse and nano- hydroxyapatite (nano-HA for the remineralization of incipient caries.After obtaining different concentrations of nano-HA (0-2-5-10%, 60 sound premolars fixed in acrylic blocks were coated with nail polish except for one surface. Ten teeth (control group were stored in distilled water and the remaining 50 samples were demineralized by immersion in 13 ml of 0.1 M lactic acid and 0.2% poly acrylic acid for 48 hours. Their microhardness was then measured and compared to that of the control group. Next, the 50 test teeth were randomly divided into 5 groups of group1 (negative, group 2 (2% nano-HA, group 3 (5% nano-HA, group 4(10% nano-HA and group 5 (0.2 NAF mouthrinse. The microhardness of the teeth was measured after 12 hours of immersion in the above-mentioned solutions. Data were analyzed using repeated measures analysis of variance (ANOVA.Microhardness of all samples decreased significantly after immersion in the demineralization solution and increased following immersion in nano-HA and NAF mouthrinses; however, this increase was not statistically significant (P=0.711.Nano-HA and NAF mouthrinses can greatly enhance remineralization and increase tooth microhardness.

  4. Corrosion of LY12 aluminum alloy in sodium chloride solution

    Institute of Scientific and Technical Information of China (English)

    程英亮; 张昭; 曹发和; 李劲风; 张鉴清; 王建明; 曹楚南

    2003-01-01

    The corrosion behavior of LY12 alloy in sodium chloride solution and its electrochemical noise were reported. The development of the micro-pits on the alloy surface was monitored by scanning electron microscopy, scanning tunneling microscopy, and electrochemical noise method. All the measurements show that the corrosion of LY12 alloy can be divided into two stages: a very reactive initial stage and a relative constant stable stage. The initial stage is corresponded to the adsorption of Cl ions and its reaction with the oxide film and the dissolution of Mg containing particles. The stable stage is corresponded to the development of the micro-pits by the galvanic attack formed by Al-Fe-Cu-Mn containing particles and the matrix. The initial stage lasts about 2-3 h while the stable stage dominates the whole corrosion process.

  5. Factors Affecting the Plasticity of Sodium Chloride, Lithium Fluoride, and Magnesium Oxide Single Crystals. 1

    Science.gov (United States)

    Stearns, Carl A.; Pack, Ann E.; Lad, Robert A.

    1959-01-01

    A study was made of the relative magnitude of the effects of various factors on the ductility of single crystals of sodium chloride (NaCl), lithium fluoride (LiF), and magnesium oxide (MgO). Specimen treatments included water-polishing, varying cleavage rate, annealing, quenching, X-irradiation, surface coating, aging, and combinations of some of these treatments. The mechanical behavior of the crystals was studied in flexure and in compression, the latter study being performed at both constant strain rate and constant load. Etch-pit studies were carried out to provide some pertinent information on the results of pretreatment on the dislocation concentration and distribution in the vicinity of the surface. The load deformation curves for these ionic single crystals show an initial region of very low slope which proved to be due to anelastic deformation. The extent of initial anelastic deformation is modified by specimen pretreatment in a way that suggests that this deformation is the result of expansion of cleaved-in dislocation loops, which can contract on the removal of the stress. The effects of the various pretreatments on the load and deflection at fracture are in accord with the prediction one might make with regard to their effect on the nucleation of fatal surface cracks. For NaCl, increases in ductility are always accompanied by increases in strength. The creep constants for NaCl are a function of treatments which affect the bulk structure but are not a function of treatments which only affect the surface.

  6. Effect of sodium fluoride ingestion on malondialdehyde concentration and the activity of antioxidant enzymes in rat erythrocytes.

    Science.gov (United States)

    Morales-González, José A; Gutiérrez-Salinas, José; García-Ortiz, Liliana; Del Carmen Chima-Galán, María; Madrigal-Santillán, Eduardo; Esquivel-Soto, Jaime; Esquivel-Chirino, César; González-Rubio, Manuel García-Luna Y

    2010-06-11

    Fluoride intoxication has been shown to produce diverse deleterious metabolic alterations within the cell. To determine the effects of sodium fluoride (NaF) treatment on malondialdehyde (MDA) levels and on the activity of antioxidant enzymes in rat erythrocytes, Male Wistar rats were treated with 50 ppm of NaF or were untreated as controls. Erythrocytes were obtained from rats sacrificed weekly for up to eight weeks and the concentration of MDA in erythrocyte membrane was determined. In addition, the activity of the enzymes superoxide, dismutase, catalase, and glutathione peroxidase were determined. Treatment with NaF produces an increase in the concentration of malondialdehyde in the erythrocyte membrane only after the eight weeks of treatment. On the other hand, antioxidant enzyme activity was observed to increase after the fourth week of NaF treatment. In conclusion, intake of NaF produces alterations in the erythrocyte of the male rat, which indicates induction of oxidative stress.

  7. Effect of Sodium Fluoride Ingestion on Malondialdehyde Concentration and the Activity of Antioxidant Enzymes in Rat Erythrocytes

    Science.gov (United States)

    Morales-González, José A.; Gutiérrez-Salinas, José; García-Ortiz, Liliana; del Carmen Chima-Galán, María; Madrigal-Santillán, Eduardo; Esquivel-Soto, Jaime; Esquivel-Chirino, César; González-Rubio, Manuel García-Luna y

    2010-01-01

    Fluoride intoxication has been shown to produce diverse deleterious metabolic alterations within the cell. To determine the effects of sodium fluoride (NaF) treatment on malondialdehyde (MDA) levels and on the activity of antioxidant enzymes in rat erythrocytes, Male Wistar rats were treated with 50 ppm of NaF or were untreated as controls. Erythrocytes were obtained from rats sacrificed weekly for up to eight weeks and the concentration of MDA in erythrocyte membrane was determined. In addition, the activity of the enzymes superoxide, dismutase, catalase, and glutathione peroxidase were determined. Treatment with NaF produces an increase in the concentration of malondialdehyde in the erythrocyte membrane only after the eight weeks of treatment. On the other hand, antioxidant enzyme activity was observed to increase after the fourth week of NaF treatment. In conclusion, intake of NaF produces alterations in the erythrocyte of the male rat, which indicates induction of oxidative stress. PMID:20640162

  8. 某铝厂氟污染土壤的植物修复研究%Discuss on Phytoremediatton of Fluoride Contaminated Soil in an Aluminum Smelter

    Institute of Scientific and Technical Information of China (English)

    尹国勋; 魏敏; 王晶; 刘克武

    2011-01-01

    [目的]研究氟污染土壤的植物修复.[方法]用离子选择电极法分析某铝厂附近土壤及植物氟化物含量.[结果]该地区土壤及植物均已受到氟化物严重污染.对17个植物样品的测定表明,样品各部位的含氟量为叶>茎>根,样品季节含氟量为夏季>冬/春季>秋季.在所研究植物中,柏树富集氟最多,其次为杨树和柳树,且植物中氟化物的污染源不仅来自于土壤,也受到大气污染的影响.[结论]为植物修复氟污染土壤提供理论依据.%[ Objective ] The aim was to study phytoremediation of fluoride contaminated soil in an aluminum smelter. [ Method ] Ion selection electrode method was selected to analyze the content of fluoride in soil and plants around an aluminum smelter. [Result]The result showed that soil and plants in this area were heavily polluted by fluoride. The research on 17 plant samples showed that, the content of absorbing fluoride of each part was leaves > stems > roots successively and the seasonal content of flouride was summer > winter/spring > autumn. cypress trees had the maximum contentof absorbing fluoride, poplars and willows second. Moreover, the pollution source of fluoride in plants was not only from soil but affected by atmospheric pollution. [ Conclusion] The study provided theory evidence for phytoremediation of fluoride contaminated soil

  9. Effect of sodium fluoride on phytase activity during germination of Pisum sativum L. seeds

    Energy Technology Data Exchange (ETDEWEB)

    Hauskrecht, I.

    1972-01-01

    The effects of fluoride ion, in concentrations varying from 0 to 4 mM F/sup -/, on phytase activity in the course of germination of Pisum sativum L. seeds and in the course of incubation in vitro are reported. The fluoride ion in 1 mM concentration cause a significant 80% decrease of the phytase activity in the incubation medium and a 24% decrease in the course of germination. The inhibition of phytase, as well as its synthesis, by fluoride ion during germination may influence the metabolism of phosphorus at the initial stage of ontogenesis.

  10. Effect of coating of aluminum carboxymethylcellulose beads on the release and bioavailability of diclofenac sodium.

    Science.gov (United States)

    Hosny, E A; al-Helw A al-R

    1998-01-01

    The production of spheres loaded with diclofenac sodium by the cross linking technique was achieved. The hydrophilic polymer sodium carboxymethylcellulose (Na-CMC) which gels in the presence of a cross linking agent, aluminum chloride (AlCl3), was used as a matrix forming agent for the bead production. To obtain a regular and uniform rate of drug release, the produced beads were coated with sodium alginate to increase the pathway of the diffused medium. Two processing variables were studied, the flocculating agent concentration (20, 40 and 60% w/v) and different coating times (15, 30 and 60 min). The results show that the higher concentrations of aluminum chloride (40 and 60% w/v) produced more uniform and rounded beads than that prepared using 20% w/v salt. The particle size of the core beads decreased insignificantly (P > 0.05) as the flocculating agent concentration increased. The coating time did not affect the particle size of the coated beads within the same concentration of aluminum chloride. The dissolution studies showed that the release rate of diclofenac sodium from the core beads increased with the increase of AlCl3 concentration and that the rate of drug release was markedly reduced after the coating of the core beads with Na-alginate. The results also show a linear relationship for drug release over a 4-5 h period from the core beads where it showed a longer straight line relationship (7 h) for the coated beads. The coating of the Al-CMC beads, prepared using 60% w/v AlCl3.6H2O, with 2% w/v aqueous solution of Na-alginate resulted in a significant (P 24 increased insignificantly (P > 0.05) from 39.82 +/- 26.61 to 57.92 +/- 25.58 micrograms h/ml resulting in a relative bioavailability of 145.45% relative to Al-CMC beads.

  11. Demons versus level-set motion registration for coronary 18F-sodium fluoride PET

    Science.gov (United States)

    Rubeaux, Mathieu; Joshi, Nikhil; Dweck, Marc R.; Fletcher, Alison; Motwani, Manish; Thomson, Louise E.; Germano, Guido; Dey, Damini; Berman, Daniel S.; Newby, David E.; Slomka, Piotr J.

    2016-03-01

    Ruptured coronary atherosclerotic plaques commonly cause acute myocardial infarction. It has been recently shown that active microcalcification in the coronary arteries, one of the features that characterizes vulnerable plaques at risk of rupture, can be imaged using cardiac gated 18F-sodium fluoride (18F-NaF) PET. We have shown in previous work that a motion correction technique applied to cardiac-gated 18F-NaF PET images can enhance image quality and improve uptake estimates. In this study, we further investigated the applicability of different algorithms for registration of the coronary artery PET images. In particular, we aimed to compare demons vs. level-set nonlinear registration techniques applied for the correction of cardiac motion in coronary 18F-NaF PET. To this end, fifteen patients underwent 18F-NaF PET and prospective coronary CT angiography (CCTA). PET data were reconstructed in 10 ECG gated bins; subsequently these gated bins were registered using demons and level-set methods guided by the extracted coronary arteries from CCTA, to eliminate the effect of cardiac motion on PET images. Noise levels, target-to-background ratios (TBR) and global motion were compared to assess image quality. Compared to the reference standard of using only diastolic PET image (25% of the counts from PET acquisition), cardiac motion registration using either level-set or demons techniques almost halved image noise due to the use of counts from the full PET acquisition and increased TBR difference between 18F-NaF positive and negative lesions. The demons method produces smoother deformation fields, exhibiting no singularities (which reflects how physically plausible the registration deformation is), as compared to the level-set method, which presents between 4 and 8% of singularities, depending on the coronary artery considered. In conclusion, the demons method produces smoother motion fields as compared to the level-set method, with a motion that is physiologically

  12. Kinetics and leaching behaviors of aluminum from pharmaceutical blisters in sodium hydroxide solution

    Institute of Scientific and Technical Information of China (English)

    王重庆; 王晖; 顾帼华; 符剑刚; 刘又年

    2015-01-01

    A hydrometallurgical process was developed for recycling pharmaceutical blisters. Leaching aluminum from pharmaceutical blisters using sodium hydroxide (NaOH) solutions was investigated with respect to leaching behaviors and kinetics. A L9(34) orthogonal design of experiments suggests that the most significant factor is NaOH concentration followed by temperature and leaching time. Factorial experiments demonstrate that the leaching rate of aluminum increases with increasing of the factors. The optimum conditions are temperature of 70 °C, leaching time of 20 min, NaOH concentration of 1.25 mol/L, liquid-to-solid mass ratio of 15:1 and agitation speed of 400 r/min. Under optimum conditions, the leaching rate is up to 100%, implying that aluminum and polyvinyl chloride (PVC) plastic in pharmaceutical blisters are separated completely. Kinetics of leaching aluminum is best described by the product layer diffusion control model, and the activation energy is calculated to be 19.26 kJ/mol.

  13. Comparative evaluation of the remineralizing efficacy of calcium sodium phosphosilicate agent and fluoride based on quantitative and qualitative analysis

    Directory of Open Access Journals (Sweden)

    Saranya Mony

    2015-01-01

    Full Text Available Background: Calcium sodium phosphosilicate (NovaMin is an agent that is claimed to release calcium and phosphate ions intraorally to help the self-repair process of enamel. It is used extensively as a desensitizing agent, but the chemical reactions that occur may promote apatite formation enhancing remineralization. The present study was undertaken to evaluate the ability of NovaMin to remineralize an experimentally induced demineralized lesion. The evaluation was done based on the quantitative and qualitative analysis of enamel over the period of 15 and 30 days. Materials and Methods: A sample of 120 noncarious premolar teeth extracted for orthodontic reasons were used for the study. Baseline data for hardness, Ca/PO 4 , and surface characteristics before and after demineralization process was obtained. All the teeth were brushed twice daily at 12 h interval with the test agents using a powered toothbrush for 2 min. The samples were tested on the 15 th and 30 th day. Results: Calcium phosphate ratio and hardness in both the groups improved during the study period. Fluoride group showed higher values for Ca/PO 4 and hardness but was not statistically significant with the P > 0.05. Scanning electron microscope pictures showed that the deposition of the material over the decalcified enamel is more smoother and uniform with NovaMin and more irregular with fluoride. Relevance: NovaMin is found to be as effective in improving the Ca/PO 4 ratio and hardness in a demineralized enamel as fluoride. Hence, it can be a new alternate material for remineralization of enamel with less toxic effects compared to fluorides.

  14. Effect of Sodium Fluoride on Bone Biomechanical and Histomorphometric Parameters and on Insulin Signaling and Insulin Sensitivity in Ovariectomized Rats.

    Science.gov (United States)

    de Cássia Alves Nunes, Rita; Chiba, Fernando Yamamoto; Pereira, Amanda Gomes; Pereira, Renato Felipe; de Lima Coutinho Mattera, Maria Sara; Ervolino, Edilson; Louzada, Mário Jefferson Quirino; Buzalaf, Marília Afonso Rabelo; Silva, Cristina Antoniali; Sumida, Doris Hissako

    2016-09-01

    Osteoporosis is a systemic disease characterized by bone degradation and decreased bone mass that promotes increased bone fragility and eventual fracture risk. Studies have investigated the use of sodium fluoride (NaF) for the treatment of osteoporosis. However, fluoride can alter glucose homeostasis. The aim of this study was to evaluate the effects of NaF intake (50 mg/L) from water on the following parameters of ovariectomized (OVX) rats: (1) tyrosine phosphorylation status of insulin receptor substrate (pp185 (IRS-1/IRS-2)) in white adipose tissue; (2) insulin sensitivity; (3) plasma concentrations of glucose, insulin, total cholesterol, triglyceride, TNF-α, IL-6, osteocalcin, calcium, and fluoride; (4) bone density and biomechanical properties in the tibia; and (5) tibia histomorphometric analysis. Fifty-two Wistar rats (2 months old) were ovariectomized and distributed into two groups: control group (OVX-C) and NaF group (OVX-F), which was subjected to treatment with NaF (50 mg/L) administered in drinking water for 42 days. The chronic treatment with NaF promoted (1) a decrease in pp185 (IRS-1/IRS-2) tyrosine phosphorylation status after insulin infusion in white adipose tissue and in insulin sensitivity; (2) an increase in the plasma concentration of insulin, fluoride, osteocalcin, calcium, triglyceride, VLDL-cholesterol, TNF-α, and IL-6; (3) a reduction in the trabecular width, bone area, stiffness, maximum strength, and tenacity; (4) no changes in body weight, food and water intake, plasma glucose, total cholesterol, HDL-cholesterol, LDL-cholesterol, bone mineral content, and bone mineral density. It was concluded that chronic treatment with NaF (50 mg/L) in OVX rats causes a decrease in insulin sensitivity, insulin signaling transduction, and biochemical, biomechanical, and histomorphometric bone parameters.

  15. Protective role of diet supplements Spirulina and Tamarind fruit pulp on kidney in sodium fluoride exposed Swiss albino mice: Histological and biochemical indices.

    Science.gov (United States)

    Yadav, N; Sharma, Shweta; Sharma, K p; Pandey, A; Pareek, P; Sharma, Subhasini

    2016-01-01

    Fluoride toxicity through potable water, particularly ground water, is not uncommon in countries such as India, China, Iran, Iraq, Turkey, parts of Africa and Afghanistan. Kidney being the main organ involved in fluoride removal, it accumulates considerable amount of fluoride. Here, we report toxic effects of oral exposure of Swiss albino mice to fluoride (sub-acute: 190 mg/kg body wt. for 7 days; and sub-chronic: 94 mg/kg body wt. for 90 days) and recovery of sub-chronic fluoride exposed mice after 90 days of sodium fluoride (NaF) withdrawal. The role of diet supplements (Spirulina and tamarind fruit pulp @ 230 mg/kg body wt. independently as well as in combination) in amelioration of fluoride toxicity has also been screened. Compared with controls, feed intake decreased from 3-43%, body wt. 4-18%, and kidney wt. 5-12% in treated mice (except diet supplement groups of sub-chronic exposure) while their water intake increased from 4-43%. Histopathological changes in the cortical region of kidney in fluoride treated mice were as follows: dilation of bowman's capsule and thickening of its parietal and visceral layer; alterations in glomeruli size and their sclerotization; increase in bowman's space; proliferation of mesangial cells; reduction in podocyte counts; and dilation of proximal and distal tubules. Fluoride exposure altered tissue biochemistry (protein, acid phosphatase and alkaline phosphatase content) and increased urea (23-58%) and creatinine content (14-127%) in the serum. Sub-acute exposure was found more toxic. The diet modulation not only reduced fluoride toxicity but also led to better recovery of treated mice after withdrawal, especially in combination.

  16. Sodium fluoride induces apoptosis in mouse embryonic stem cells through ROS-dependent and caspase- and JNK-mediated pathways

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen Ngoc, Tam Dan [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Son, Young-Ok [Graduate Center for Toxicology, School of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); Lim, Shin-Saeng [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Department of Bioactive Material Sciences and Research Center of Bioactive Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Shi, Xianglin [Graduate Center for Toxicology, School of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); Kim, Jong-Ghee [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Heo, Jung Sun [Department of Maxillofacial Biomedical Engineering and Institute of Oral Biology, School of Dentistry, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Choe, Youngji [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Jeon, Young-Mi, E-mail: young@jbnu.ac.kr [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Lee, Jeong-Chae, E-mail: leejc88@jbnu.ac.kr [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Graduate Center for Toxicology, School of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); Department of Bioactive Material Sciences and Research Center of Bioactive Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of)

    2012-03-15

    Sodium fluoride (NaF) is used as a source of fluoride ions in diverse applications. Fluoride salt is an effective prophylactic for dental caries and is an essential element required for bone health. However, fluoride is known to cause cytotoxicity in a concentration-dependent manner. Further, no information is available on the effects of NaF on mouse embryonic stem cells (mESCs). We investigated the mode of cell death induced by NaF and the mechanisms involved. NaF treatment greater than 1 mM reduced viability and DNA synthesis in mESCs and induced cell cycle arrest in the G{sub 2}/M phase. The addition of NaF induced cell death mainly by apoptosis rather than necrosis. Catalase (CAT) treatment significantly inhibited the NaF-mediated cell death and also suppressed the NaF-mediated increase in phospho-c-Jun N-terminal kinase (p-JNK) levels. Pre-treatment with SP600125 or z-VAD-fmk significantly attenuated the NaF-mediated reduction in cell viability. In contrast, intracellular free calcium chelator, but not of sodium or calcium ion channel blockers, facilitated NaF-induced toxicity in the cells. A JNK specific inhibitor (SP600125) prevented the NaF-induced increase in growth arrest and the DNA damage-inducible protein 45α. Further, NaF-mediated loss of mitochondrial membrane potential was apparently inhibited by pifithrin-α or CAT inhibitor. These findings suggest that NaF affects viability of mESCs in a concentration-dependent manner, where more than 1 mM NaF causes apoptosis through hydroxyl radical-dependent and caspase- and JNK-mediated pathways. -- Highlights: ► The mode of NaF-induced cell death and the mechanisms involved were examined. ► NaF induced mainly apoptotic death of mouse embryonic stem cells (mESCs). ► NaF induced mitochondrial-mediated and caspase-dependent apoptosis. ► JNK- and p53-mediated pathways are involved in NaF-mediated apoptosis in the cells. ► ROS are the up-stream effector in NaF-mediated activation of JNK and p53 in mESCs.

  17. 铝电解生产降低氟化铝消耗的实践探索%Practice and Exploration on Lowering Consumption of Aluminum Fluoride during Aluminum Production

    Institute of Scientific and Technical Information of China (English)

    杨刚

    2014-01-01

    通过对氟化铝在电解过程的消耗,分析了氟化铝的利用率较低的原因,从原材料水分控制、降低电解生产温度、减少效应系数、保持合理分子比、提高烟气净化回收率等方面着手,提高了氟化铝的利用率,降低了氟化铝的消耗,以及减少环境污染。%T he present paper discusses causes of low utilizing of aluminum fluoride during aluminum production . Consumption of aluminum fluoride is lowered by some operation practices , such as quality control of raw materials , lowering electrolysis temperature , fewer anode effects , proper mole ratio , improving efficiency of pot fume treat-ment . Therefore , this reduces the cost of aluminum production and lessens environmental pollution .

  18. Limited evidence for the effect of sodium fluoride on deterioration of hearing loss in patients with otosclerosis: a systematic review of the literature

    NARCIS (Netherlands)

    Hentschel, M.A.; Huizinga, P.; van der Velden, D.L.; Wegner, I.; Bittermann, A.J.N.; van der Heijden, G.J.M.; Grolman, W.

    2014-01-01

    OBJECTIVE: To determine the protective effect of sodium fluoride on the deterioration of hearing loss in adult patients with otosclerosis. DATA SOURCES: PubMed, Embase, the Cochrane Library, and CINAHL. STUDY SELECTION: A systematic literature search was conducted. Studies reporting original study d

  19. Storage of specimens at 4 degrees C or addition of sodium fluoride (1%) prevents formation of ethanol in urine inoculated with Candida albicans.

    Science.gov (United States)

    Jones, A W; Hylén, L; Svensson, E; Helander, A

    1999-09-01

    The microbial synthesis of ethanol was investigated in urine specimens containing 0.5% or 1.0% (w/v) glucose and inoculated with the yeast Candida albicans (100 cfu/mL). Aliquots (10 mL) of urine were dispensed into plastic tubes containing enough sodium fluoride to give final concentrations of 0.1%, 0.25%, 0.5%, 0.75%, 1%, and 2% (w/v), and C. albicans was added. The tubes were tightly stoppered and allowed to stand either at room temperature (22 degrees C) or in a refrigerator (4 degrees C) for up to 34 days before concentrations of ethanol were determined by headspace gas chromatography. Urine samples stored at 22 degrees C without sodium fluoride produced 0.25 g/L ethanol after two days, and the concentration increased to 2.10 g/L and 4.50 g/L after eight days for specimens containing 0.5% (w/v) and 1% (w/v) glucose, respectively. The ratio of the serotonin metabolites 5-hydroxytryptophol/5-hydroxyindoleacetic acid (5HTOL/5HIAA) in urine remained within the reference range (Urine samples kept at 4 degrees C did not produce any ethanol (albicans was stopped completely by adding 1% or 2% (w/v) sodium fluoride but not by concentrations of 0.75% (w/v) or less. The microbial synthesis of ethanol in urine samples initially stored at room temperature without sodium fluoride was slowed down considerably by moving them into a refrigerator at 4 degrees C. In conclusion, the production of ethanol in urine by C. albicans can be prevented by storage of samples in a refrigerator at 4 degrees C or by adding sodium fluoride > or = 1% (w/v). Measuring the ratio of 5HTOL/5HIAA can help to distinguish postsampling production of ethanol from metabolism and excretion processes.

  20. Partial molar volume and partial molar compressibility of four homologous {alpha}-amino acids in aqueous sodium fluoride solutions at different temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Rajagopal, K., E-mail: krpal25@yahoo.co [Department of Physics, Government College of Engg., Tirunelveli 627 007, Tamilnadu (India); Edwin Gladson, S., E-mail: aseg_win@rediffmail.co [Department of Physics, St. Xavier' s Catholic College of Engg., Chunkankadai 629 003, Tamilnadu (India)

    2011-06-15

    Research highlights: Partial molar volume indicates strong solute-cosolute interaction in the NaF solution. Partial molar compressibility results compliment partial molar volume results. Hydration number proves that sodium fluoride has dehydration effect on amino acids. Interactions between sodium fluoride and (NH{sub 3}{sup +},COO{sup -}) group of amino acid are stronger. - Abstract: Density and ultrasonic speed of four amino acids (glycine, L-alanine, L-valine, and L-leucine) in aqueous sodium fluoride solutions {l_brace}(0.1 to 0.5) M{r_brace} have been measured at T = (308.15, 313.15, and 318.15) K. Apparent molar volumes (V{sub {phi}}), partial molar volumes (V{sub {phi}}{sup 0}), transfer volumes ({Delta}V{sub {phi}}{sup 0}) and hydration number (n{sub H}) are evaluated using density data. Adiabatic compressibility ({beta}{sub s}), change ({Delta}{beta}{sub s}), and relative change in compressibility ({Delta}{beta}{sub s}/{beta}{sub 0}), apparent molar compressibility (K{sub {phi}}), partial molar compressibility (K{sub {phi}}{sup 0}), transfer compressibility ({Delta}K{sub {phi}}{sup 0}), and hydration number (n{sub H}) have been calculated using ultrasonic speed data. The linear correlation of V{sub {phi}}{sup 0},{Delta}V{sub {phi}}{sup 0},K{sub {phi}}{sup 0} and {Delta}K{sub {phi}}{sup 0} for a homologous series of amino acids have been used utilised to calculate the contribution of charged end groups (NH{sub 3}{sup +}, COO{sup -}), CH{sub 2} group and other alkyl chain of the amino acids. The analysis shows that the ion-ion interactions are much stronger than ion-hydrophobic interactions over the entire concentration range of sodium fluoride. It is observed that sodium fluoride has a strong dehydration effect on amino acids.

  1. A rich detector with a sodium fluoride radiator:. pi. /K identification up to 3 GeV/c

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, R.; Guyonnet, J.L.; Giomataris, Y.; Petroff, P.; Seguinot, J.; Tocqueville, J.; Ypsilantis, T.

    1987-10-01

    The use of a single crystal of sodium fluoride (NaF) as a Cherenkov radiator has been investigated. Its transparency has been measured and found to be good for photon energies below 9.8 eV. Data on its index of refraction are well fitted to a single-pole Sellmeier resonance formula. These data allow a realistic Monte Carlo simulation of a proximity-focused ring imaging Cherenkov (RICH) system. The photon detector is a multiwire proportional chamber (MWPC) with pad readout. The photosensitive gases considered are tetrakis(dimethylamine)ethylene (TMAE) and triethylamine (TEA). The simulation shows that system having 10 cm radial thickness and 10% of a radiation length of material would identify pions and kaons below 3 GeV/c momentum. The pad dimensions required are about 5 mm /times/ 5 mm. 4 refs., 10 figs.

  2. Impact of Personal Characteristics and Technical Factors on Quantification of Sodium 18F-Fluoride Uptake in Human Arteries

    DEFF Research Database (Denmark)

    Blomberg, Björn Alexander; Thomassen, Anders; de Jong, Pim A

    2015-01-01

    Sodium (18)F-fluoride ((18)F-NaF) PET/CT imaging is a promising imaging technique for assessment of atherosclerosis, but is hampered by a lack of validated quantification protocols. Both personal characteristics and technical factors can affect quantification of arterial (18)F-NaF uptake....... This study investigated if blood activity, renal function, injected dose, circulating time, and PET/CT system affect quantification of arterial (18)F-NaF uptake. METHODS: Eighty-nine healthy subjects were prospectively examined by (18)F-NaF PET/CT imaging. Arterial (18)F-NaF uptake was quantified...... at the level of the ascending aorta, aortic arch, descending thoracic aorta, and coronary arteries by calculating the maximum (18)F-NaF activity (NaFmax), the maximum target-to-background ratio (TBRmax/mean), and the maximum blood subtracted (18)F-NaF activity (bsNaFmax). Multivariable linear regression...

  3. Influence of enamel matrix derivative (Emdogain) and sodium fluoride on the healing process in delayed tooth replantation: histologic and histometric analysis in rats.

    Science.gov (United States)

    Poi, Wilson Roberto; Carvalho, Roberta Martinelli; Panzarini, Sônia Regina; Sonoda, Celso Koogi; Manfrin, Thais Mara; Rodrigues, Thais da Silveira

    2007-02-01

    Although it has already been shown that enamel matrix derivative (Emdogain) promotes periodontal regeneration in the treatment of intrabony periodontal defects, there is little information concerning its regenerative capacity in cases of delayed tooth replantation. To evaluate the alterations in the periodontal healing of replanted teeth after use of Emdogain, the central incisors of 24 Wistar rats (Rattus norvegicus albinus) were extracted and left on the bench for 6 h. Thereafter, the dental papilla and the enamel organ of each tooth were sectioned for pulp removal by a retrograde way and the canal was irrigated with 1% sodium hypochlorite. The teeth were assigned to two groups: in group I, root surface was treated with 1% sodium hypochlorite for 10 min (changing the solution every 5 min), rinsed with saline for 10 min and immersed in 2% acidulated-phosphate sodium fluoride for 10 min; in group II, root surfaces were treated in the same way as described above, except for the application of Emdogain instead of sodium fluoride. The teeth were filled with calcium hydroxide (in group II right before Emdogain was applied) and replanted. All animals received antibiotic therapy. The rats were killed by anesthetic overdose 10 and 60 days after replantation. The pieces containing the replanted teeth were removed, fixated, decalcified and paraffin-embedded. Semi-serial 6-microm-thick sections were obtained and stained with hematoxylin and eosin for histologic and histometric analyses. The use of 2% acidulated-phosphate sodium fluoride provided more areas of replacement resorption. The use of Emdogain resulted in more areas of ankylosis and was therefore not able to avoid dentoalveolar ankylosis. It may be concluded that neither 2% acidulated-phosphate sodium fluoride nor Emdogain were able to prevent root resorption in delayed tooth replantation in rats.

  4. ELECTROCHEMICAL NOISE ANALYSIS OF PURE ALUMINUM IN SODIUM CHLORIDE SOLUTION WITH WAVELET TRANSFORM TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    Z. Zhang; Q.D. Zhong; J.Q. Zhang; Y.L. Cheng; F.H. Cao; J.M. Wang; C.N. Cao

    2002-01-01

    Wavelet transforms (WT) are proposed as an alternative tool to overcome the limita-tions of Fourier transforms (FFT) in the analysis of electrochemical noise (EN) data.The most relevant feature of this method of analysis is its capability of decomposingelectrochemical noise records into different sets of wavelet coefficients, which containinformation about the time scale characteristic of the associated corrosion event. Inthis context, the potential noise fluctuations during the free corrosion of pure alu-minum in sodium chloride solution was recorded and analyzed with wavelet transformtechnique. The typical results showed that the EN signal is composed of distinct typeof events, which can be classified according to their scales, i.e. their time constants.Meanwhile, the energy distribution plot (EDP) can be used as "fingerprints" of ENsignals and can be very useful for analyzing EN data in the future.

  5. Toxicity detection of sodium nitrite, borax and aluminum potassium sulfate using electrochemical method

    Institute of Scientific and Technical Information of China (English)

    Dengbin Yu; Daming Yong; Shaojun Dong

    2013-01-01

    Based on the inhibition effect on the respiratory chain activity of microorganisms by toxicants,an electrochemical method has been developed to measure the current variation of a mediator in the presence of microorganisms contacted with a toxicant.Microelectrode arrays were adopted in this study,which can accelerate the mass transfer rate of an analyte to the electrode and also increase the total current signal,resulting in an improvement in detection sensitivity.We selected Escherichia coli as the testee and the standard glucoseglutamic acid as an exogenous material.Under oxygen restriction,the experiments in the presence of toxicant were performed at optimum conditions (solution pH 7.0,37℃ and reaction for 3 hr).The resulting solution was then separated from the suspended microorganisms and was measured by an electrochemical method,using ferricyanide as a mediator.The current signal obtained represents the re oxidation of ferrocyanide,which was transformed to inhibiting efficiency,IC50,as a quantitative measure of toxicity.The IC50 values measured were 410,570 and 830 mg/L for sodium nitrite,borax and aluminum potassium sulfate,respectively.The results show that the toxicity sequence for these three food additives is consistent with the value reported by other methods.Furthermore,the order of damage degree to the microorganism was also observed to be:sodium nitrite > borax > aluminum potassium sulfate >blank,according to the atomic force microscopy images of E.coli after being incubated for 3 hr with the toxic compound in buffer solutions.The electrochemical method is expected to be a sensitive and simple alternative to toxicity screening for chemical food additives.

  6. 铝型材生产含氟废水处理研究%Study on Treatment of Fluoride Waste Water rfom Aluminum Production

    Institute of Scientific and Technical Information of China (English)

    张丽莉; 赵旭德; 王静; 黄庆慧

    2013-01-01

    In order to treat the fluoride waste water produced by aluminum production to meet the requirment [ F -]≤ 20 mg· L -1 ,CaCl2 was used to remove fluoride in wastewater ,the treatment result of fluoride ionic was analyzed under different condition .The results showed that the value of pH should be controlled between 6.0and 8.0,and when fluorine ionic concentration was 200 ~300mg· L -1,the quality ratio of CaCl 2 and fluoride ion was 4∶1 .the quality ratio of CaCl 2 and fluoride ion increased when fluorine ionic concentration was <150 mg· L -1,the precipitation time should be longer than 2 hours.%为使铝型材生产产生的含氟废水经处理后达到[F -]≤20 mg· L -1的要求,采用CaCl2进行除氟处理,对不同工艺条件下含氟废水的处理效果进行分析。结果表明:pH值范围宜控制在6.0~8.0之间,当氟单离子浓度在200~300 mg· L -1时,投加CaCl2的量与F -质量比为4∶1;当氟单离子浓度<150 mg· L -1时,需增大CaCl2的投加量,沉淀时间应≥2 h。

  7. The effects of a new therapeutic triclosan/copolymer/sodium-fluoride dentifrice on oral bacteria, including odorigenic species.

    Science.gov (United States)

    Furgang, David; Sreenivasan, Prem K; Zhang, Yun Po; Fine, Daniel H; Cummins, Diane

    2003-09-01

    This investigation examined the in vitro and ex vivo antimicrobial effects of a new dentifrice, Colgate Total Advanced Fresh, formulated with triclosan/copolymer/sodium fluoride, on oral bacteria, including those odorigenic bacteria implicated in bad breath. The effects of Colgate Total Advanced Fresh were compared to commercially available fluoride dentifrices that served as controls. Three experimental approaches were undertaken for these studies. In the first approach, the dentifrice formulations were tested in vitro against 13 species of oral bacteria implicated in bad breath. The second approach examined the antimicrobial activity derived from dentifrice that was adsorbed to and released from hydroxyapatite disks. In this approach, dentifrice-treated hydroxyapatite disks were immersed in a suspension of bacteria, and reduction in bacterial viability from the release of bioactive agents from hydroxyapatite was determined. The third approach examined the effect of treating bacteria immediately after their removal from the oral cavity of 11 adult human volunteers. This ex vivo study examined the viability of cultivable oral bacteria after dentifrice treatment for 2 minutes. Antimicrobial effects were determined by plating Colgate Total Advanced Fresh and control-dentifrice-treated samples on enriched media (for all cultivable oral bacteria) and indicator media (for hydrogen-sulfide-producing organisms), respectively. Results indicated that the antimicrobial effects of Colgate Total Advanced Fresh were significantly greater than either of the other dentifrices for all 13 oral odorigenic bacterial strains tested in vitro (P Colgate Total Advanced Fresh-treated hydroxyapatite disks were significantly more active in reducing bacterial growth than the other dentifrices tested (P oral bacteria with Colgate Total Advanced Fresh demonstrated a 90.9% reduction of all oral cultivable bacteria and a 91.5% reduction of oral bacteria producing hydrogen sulfide compared with

  8. A Comparison of Antibacterial Efficacy of 0.5% Sodium Fluoride Impregnated Miswak and Plain Miswak Sticks on Streprococcus mutans - A Randomized Controlled Trial

    Science.gov (United States)

    Kumar, Vinod; Krishna, Madhusudan; Raina, Sakshi; Jaiswal, Ashish; Selvan, Arul; Patil, Chaitra; Kalgotra, Sneh

    2017-01-01

    Introduction Miswak (Salvadora persica) is a tooth cleaning stick made from the Salvodora Persica tree. It serves as a natural dentifrice with anti-bacterial, anti-plaque and anti-fungal properties. Fluoride, impregnated in chewing sticks will bestow comparable safety against dental caries as the fluoride containing dentifrice. Aim The aim of the present study was to assess and compare the anti-bacterial effect of 0.5% sodium fluoride impregnated miswak and plain miswak sticks on Streptococcus mutans. Materials and Methods A randomized controlled concurrent parallel triple blind clinical trial was conducted for a period of 8 days. The trial included 30 subjects aged 20–23 years, who were randomly allocated in 1:1 ratio to Group A [0.5% Sodium Fluoride (NaF) impregnated Miswak sticks) and Group B (Plain Miswak sticks) respectively. The participants were instructed to chew miswak sticks for 6 minutes in the morning before breakfast. Unstimulated saliva was collected at baseline and after chewing miswak sticks to estimate S. mutans count using Mitis Salivarius Bacitracin agar. Data was statistically analyzed using paired and unpaired t-test. Results A statistically significant reduction in S. mutans Colony Forming Units (CFU) count in saliva was observed after using fluoridated miswak sticks compared to the baseline count (p=0.001). There was no significant difference in anti-bacterial effect of fluoridated miswak sticks and plain miswak sticks on S. mutans count (p=0.58). Conclusion The efficacy of miswak impregnated with 0.5% NaF and plain miskaw sticks in reducing S. mutans counts in saliva is analogous.

  9. Investigation on water fluoride content around a aluminum enterprise and in vivo fluoride content of residents%某铝业周边水氟含量及居民体内氟含量的调查

    Institute of Scientific and Technical Information of China (English)

    何胜; 栗小原; 杨彩梅; 玉莹; 林洁; 廖娟; 吕庚珉; 张树球

    2012-01-01

    [ Objective] Through determination of water fluoride content around a aluminum enterprise and urinary fluoride content of residents, to study the effect of industrial production on surrounding environment and human health as well as the industrial zone location. [ Methods] The collection of river water, well water, tap water around a aluminum enterprise and the morning urine of residents living 1 000 m and 10 000 m away from the aluminum enterprise in each direction was used to determine fluoride concentration by fluoride ion selective electrode method. The measurement of residents living 1 000 m away from the enterprise in west was performed twice with interval of 30 days, that was performed on 2 groups of residents living 1 000 m away from the enterprise in west, and the well water fluoride concentration in endemic fluorosis area of northeast China was taken as the measurement control. [Results]The fluorine (F) content [x ±s) of industrial zone upstream river, downstream river, well water, tap water, water in endemic fluorosis area were 0.103 ±0.004, 0.171 ±0.003, 0.066 ±0.002, 0.053 ± 0.001, 1.183 ±0.029 (mg/L) , water fluoride in endemic fluorosis area was significantly higher than that of plant water fluoride (P 0.05). Urinary fluoride (χ ± s) of 3 groups of residents living 1 000, 10 000 meters away in west was 1.71 ±0.76 mg/L, 0.42 ±0.22 mg/L, 0.47 ±0.30 mg/L, respectively. The 1 000 meters group was significantly higher than 2 groups of 100 000 meter(P<0.01). [Conclusion] Water fluoride content is high in downstream river of industrial zone. And it of leeward west group is significantly higher than that of the windward east group and north group. The aluminum industry causes obvious effect on in vivo fluoride metabolism among nearby residents, but no effect among residents living over a distance (10 000 m).%目的 通过对某电解铝厂附近水氟及居民点居民尿氟的测定,研究工业生产对周边环境和人体健康的影响

  10. The effect of casein phosphopeptide-amorphous calcium phosphate paste and sodium fluoride mouthwash on the prevention of dentine erosion: An in vitro study

    Directory of Open Access Journals (Sweden)

    Maryam Moezizadeh

    2014-01-01

    Full Text Available Aim: The purpose was to compare the effect of 0.2% sodium fluoride mouthwash and casein phosphopeptide-amorphous calcium phosphate paste on prevention of dentin erosion. Materials and Methods: Buccal surfaces of 36 sound premolar teeth were ground flat and polished with abrasive discs. Half the polished surfaces were covered with tape to maintain a reference surface. Samples were randomly allocated into three groups. Group A was pretreated with tooth mousse (TM 4 times a day for 5 days. Group B was pretreated with 0.2% sodium fluoride mouthwash 4 times a day for 5 days. Group C was considered as the control group with no pretreatment. In the next step, the samples were exposed to Coca-Cola 4 times a day for 3 days. After each erosive cycle, the samples were rinsed with deionized water and stored in artificial saliva. The surface loss was determined using profilometry. Results: The erosion in both Groups A and B was less than the control group. The surface loss in mouthwash group was significantly lower than in the control group. Erosion in TM group was more than the mouthwash group and less than the control group. Conclusion: Sodium fluoride mouthwash is more effective for prevention of dentin erosion.

  11. Formation mechanism and luminescence properties of nanostructured sodium yttrium fluoride corn sticks synthesized by precipitation transformation method

    Institute of Scientific and Technical Information of China (English)

    田俐; 赵瑞妮; 王金晶; 陈琳; 薛建荣; 肖秋国

    2015-01-01

    Monodisperse sodium yttrium fluoride corn sticks with hexagonal nanostructure were successfully prepared by a facile and repeatable precipitation transformation method. The phase and morphology of the products were characterized with X-ray diffraction (XRD) and scanning electron microscopy (SEM). The growth mechanism was studied, indicating that the initial generated Y(OH)3 gradually translated into YF3 and then transformed into corn stick-like H-NaYF4 nanoparticles owing to the crucial role of fluorine ions in the solution. The up-conversion (UC) luminescence properties of H-NaYF4:20%Yb3+,2%Er3+ nanocrystals were discussed. The intensive green emission in the range of 510–570 nm was attributed to the (2H11/2,4S3/2)→4I15/2 transition and the weaker red emission between 640 and 680 nm was originating from the4F9/2→4I15/2 transition.

  12. In vitro effect of sodium fluoride on malondialdehyde concentration and on superoxide dismutase, catalase, and glutathione peroxidase in human erythrocytes.

    Science.gov (United States)

    Gutiérrez-Salinas, José; García-Ortíz, Liliana; Morales González, José A; Hernández-Rodríguez, Sergio; Ramírez-García, Sotero; Núñez-Ramos, Norma R; Madrigal-Santillán, Eduardo

    2013-01-01

    The aim of this paper was to describe the in vitro effect of sodium fluoride (NaF) on the specific activity of the major erythrocyte antioxidant enzymes, as well as on the membrane malondialdehyde concentration, as indicators of oxidative stress. For this purpose, human erythrocytes were incubated with NaF (0, 7, 28, 56, and 100 μg/mL) or NaF (100 μg/mL) + vitamin E (1, 2.5, 5 and 10 μg/mL). The malondialdehyde (MDA) concentration on the surface of the erythrocytes was determined, as were the enzymatic activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GlPx). Our results demonstrated that erythrocytes incubated with increasing NaF concentrations had an increased MDA concentration, along with decreased activity of antioxidant enzymes. The presence of vitamin E partially reversed the toxic effects of NaF on erythrocytes. These findings suggest that NaF induces oxidative stress in erythrocytes in vitro, and this stress is partially reversed by the presence of vitamin E.

  13. Prophylactic effects of pomegranate (Punica granatum) juice on sodium fluoride induced oxidative damage in liver and erythrocytes of rats.

    Science.gov (United States)

    Bouasla, Asma; Bouasla, Ihcène; Boumendjel, Amel; Abdennour, Cherif; El Feki, Abdelfattah; Messarah, Mahfoud

    2016-07-01

    The objective of this study was to investigate the protective effects of pomegranate (Punica granatum) juice (PGJ) on oxidative damages in liver tissue and erythrocytes of rats intoxicated by sodium fluoride (NaF). Rats were randomly divided into two groups: group I received standard diet and group II received orally 1 mL of PGJ. After 5 weeks of pretreatment, each group was divided again into two subgroups and treated for another 3 weeks as follows: group I was subdivided into a control group and a group that was treated with 100 ppm of NaF (in drinking water); group II was subdivided into one group that was treated daily with both 100 ppm NaF and PGJ (1 mL orally) and one that received daily 1 mL of pomegranate juice. Exposure to NaF decreased hematological parameters, changed the total protein, albumin, bilirubin levels, and increased the activities of hepatic marker enzymes. We also noted an increase in lipid peroxidation contents, accompanied by a decrease of reduced glutathione levels. Antioxidant enzyme activities in both tissues were modified in the NaF group compared with the control group. However, the administration of PGJ juice caused an amelioration of the previous parameters. Our results indicated the potential effects of NaF to induce oxidative damage in tissues and the ability of PGJ to attenuate NaF-induced oxidative injury.

  14. Genes and Gene Networks Involved in Sodium Fluoride-Elicited Cell Death Accompanying Endoplasmic Reticulum Stress in Oral Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Yoshiaki Tabuchi

    2014-05-01

    Full Text Available Here, to understand the molecular mechanisms underlying cell death induced by sodium fluoride (NaF, we analyzed gene expression patterns in rat oral epithelial ROE2 cells exposed to NaF using global-scale microarrays and bioinformatics tools. A relatively high concentration of NaF (2 mM induced cell death concomitant with decreases in mitochondrial membrane potential, chromatin condensation and caspase-3 activation. Using 980 probe sets, we identified 432 up-regulated and 548 down-regulated genes, that were differentially expressed by >2.5-fold in the cells treated with 2 mM of NaF and categorized them into 4 groups by K-means clustering. Ingenuity® pathway analysis revealed several gene networks from gene clusters. The gene networks Up-I and Up-II included many up-regulated genes that were mainly associated with the biological function of induction or prevention of cell death, respectively, such as Atf3, Ddit3 and Fos (for Up-I and Atf4 and Hspa5 (for Up-II. Interestingly, knockdown of Ddit3 and Hspa5 significantly increased and decreased the number of viable cells, respectively. Moreover, several endoplasmic reticulum (ER stress-related genes including, Ddit3, Atf4 and Hapa5, were observed in these gene networks. These findings will provide further insight into the molecular mechanisms of NaF-induced cell death accompanying ER stress in oral epithelial cells.

  15. 总离子强度缓冲体系中柠檬酸钠浓度对水氟测定的影响%Influence of sodium citrate concentration in TISAB on detection of water fluoride

    Institute of Scientific and Technical Information of China (English)

    张卫国; 李雪春; 林野

    2013-01-01

    Objective To observe the influence of sodium citrate concentrations in TISAB on detection of water fluoride,and to explore the feasibility of 0.10 mol/L sodium citrate buffer system in detection of water fluoride.Methods Under pH 5.0 to 5.5,a series of fluoride standards of 0.2,0.5,1.0,2.0 and 5.0 mg/L were measured when sodium citrate concentration was 0.01,0.10,and 1.00 mol/L in the TISAB system.The results of water fluoride measurement were compared,recovery calculated and regression equation of the standard curve was set up.The feasibility of 0.10 mol/L sodium citrate in the TISAB system to detect water fluoride was tested,including interference test,accuracy,confidence limits,as well as precision test.Water fluoride was determined by fluoride ion selective electrode according to the "Standard Test Methods for Drinking Water" (GB/T 5750.5-2006).Results When the sodium citrate concentrations in the TISAB system were 0.01,0.10 and 1.00 mol/L,and the concentrations of fluoride in the sample were 0.2,0.5,1.0,2.0 and 5.0 mg/L,recoveries of water fluoride were 96.0%,103.0%,179.5%; 80.6%,97.8%,132.2%; 73.3%,97.0%,103.0%; 70.0%,100.0%,87.5%; and 66.4%,102.0%,65.4%.The equation of linear regression was y =lg-1(226.4-E/47.4),y =lg-1(226.4-E/53.4) and y =lg-1(208.1-E/36.9) ; the correlation coefficient(r) were 0.9993,0.9999 and 0.9993.The minimum detectable concentration and limit of quantitation was 0.023 and 0.072 mg/L when sodium citrate was 0.10 mol/L in the TISAB system.Aluminum(Al3+,100 μg),ferrum(Fe3+,800 μg),calcium(Ca2+,1200 μg),Al3+(50 μg) + Fe3+ (800 μg),Al3+(50 μg) + Ca2+(1200 μg) can be masked when sodium citrate was 0.10 mol/L in the TISAB system.The total average recoveries confidence limit R/d was 0.99.The total standard deviation of standard solution,water sample and spiked water sample was less than 5% of their respective mean concentration.Conclusions High concentration of sodium citrate buffer system has a

  16. K+-Na+ ion-exchanged sodium magnesium aluminum germanate glass waveguide amplifier operating in the first telecommunications window

    Science.gov (United States)

    Yang, Dianlai; Zhang, Jie; Pun, Edwin Yue-Bun; Lin, Hai

    2010-12-01

    Potassium-sodium (K+-Na+) ion-exchanged multimode channel waveguide amplifiers have been fabricated based on Tm3+/Yb3+ codoped sodium magnesium aluminum germanate (NMAG) glass substrates. The normalized optical and relative gain coefficients of a 2.20 cm long device were identified to be 3.65 dB/cm and 1.58 dB/cm, respectively, at a signal wavelength of 810 nm under 457 mW 980 nm laser diode excitation. These are the highest values reported, and the results indicate that Tm3+/Yb3+ codoped NMAG glasses are an attractive material for optical amplification in the first telecommunications window.

  17. EVOLUTION OF THE ELECTROCHEMICAL CHARACTERISTICS DURING PITTING CORROSION OF PURE ALUMINUM IN SODIUM CHLORIDE SOLUTION

    Institute of Scientific and Technical Information of China (English)

    Z. Zhang; C. Cai; F.H. Cao; Z.N. Gao; J.Q. Zhang; C.N. Cao

    2005-01-01

    The corrosion behavior of pure aluminum in neutral 3.0% (mass fraction) sodium chloride (NaCl) solution has been studied using electrochemical impedance spectroscopy (ELS) measurement in conjunction with the scanning electron microscopy (SEM) technique. EIS information on the evolution of pitting corrosion over a period of 15 days has been obtained and analyzed with equivalent circuit technique. The results shown that, during the ensemble constant immersion time, two time constants involved, the high frequency one originated from the protective layer on the corroding surface while the low frequency one from the diffusion process or the corrosion reaction and so on. And there existed a period for oxide film to growth and thickening prior to the commencement of the attacking of chloride ions to the substrate. Meanwhile, good relationship between EIS and the material corrosion type/severity has been obtained, which has been interpreted according to the characteristics of corrosion process such as auto acceleration of pitting corrosion and the protection of local anodic reaction to the area around them.

  18. A critical study on borosilicate glassware and silica-based QMA's in nucleophilic substitution with [{sup 18}F]fluoride: influence of aluminum, boron and silicon on the reactivity of [{sup 18}F]fluoride

    Energy Technology Data Exchange (ETDEWEB)

    Svadberg, A., E-mail: anders.svadberg@uit.n [University of Tromso, Institute of Pharmacy, Department of Pharmaceutics and Biopharmaceutics, N-9037 Tromso (Norway); Clarke, A.; Dyrstad, K.; Martinsen, I. [GE Healthcare MDx R and D, Nycoveien 2, NO-0401 Oslo (Norway); Hjelstuen, O.K. [University of Tromso, Institute of Pharmacy, Department of Pharmaceutics and Biopharmaceutics, N-9037 Tromso (Norway); GE Healthcare MDx R and D, Nycoveien 2, NO-0401 Oslo (Norway)

    2011-02-15

    Leachables of borosilicate glassware and silica-based anion exchange columns (QMAs) may influence nucleophilic substitution with [{sup 18}F]fluoride ([{sup 18}F]F{sup -}). Aluminum, boron and silicon, all constituents of borosilicate glass, were found as water soluble leachables in a typical PET synthesis setup. Relevant ranges of the leachable quantities were studied based on an experimental design, in which species of the three elements were added to the labeling of the precursor for anti-1-amino-3-[{sup 18}F]fluorocyclobutyl-1-carboxylic acid ([{sup 18}F]FACBC). Levels of 0.4-2 ppm aluminum as AlCl{sub 3} had a strong negative influence on labeling yield while 4-20 ppm of boron as KBO{sub 2} and 50-250 ppm of silicon as Na{sub 2}SiO{sub 3} did not have a significant impact. Interesting interaction effects between the elements were observed, where particularly KBO{sub 2} reduced the negative effect of AlCl{sub 3} on labeling yield. It can be concluded that leachables of borosilicate glassware easily can influence nucleophilic substitution with n.c.a. [{sup 18}F]F{sup -} and give variable yields.

  19. A critical study on borosilicate glassware and silica-based QMA's in nucleophilic substitution with [18F]fluoride: influence of aluminum, boron and silicon on the reactivity of [18F]fluoride.

    Science.gov (United States)

    Svadberg, A; Clarke, A; Dyrstad, K; Martinsen, I; Hjelstuen, O K

    2011-02-01

    Leachables of borosilicate glassware and silica-based anion exchange columns (QMAs) may influence nucleophilic substitution with [(18)F]fluoride ([(18)F]F(-)). Aluminum, boron and silicon, all constituents of borosilicate glass, were found as water soluble leachables in a typical PET synthesis setup. Relevant ranges of the leachable quantities were studied based on an experimental design, in which species of the three elements were added to the labeling of the precursor for anti-1-amino-3-[(18)F]fluorocyclobutyl-1-carboxylic acid ([(18)F]FACBC). Levels of 0.4-2 ppm aluminum as AlCl(3) had a strong negative influence on labeling yield while 4-20 ppm of boron as KBO(2) and 50-250 ppm of silicon as Na(2)SiO(3) did not have a significant impact. Interesting interaction effects between the elements were observed, where particularly KBO(2) reduced the negative effect of AlCl(3) on labeling yield. It can be concluded that leachables of borosilicate glassware easily can influence nucleophilic substitution with n.c.a. [(18)F]F(-) and give variable yields.

  20. Two-photon-absorption cross section of Nd3+ in yttrium aluminum garnet and yttrium lithium fluoride near 1.06 μm

    Science.gov (United States)

    Chase, L. L.; Payne, Stephen A.

    1986-12-01

    We have measured the spectrally integrated two-photon-absorption (TPA) cross sections for the 4I9/2--> 4G7/2 transitions of Nd3+ and obtained values of 1.2×10-40 and 0.15×10-40 cm4 for Nd3+-doped yttrium aluminum garnet (YAG) and yttrium lithium fluoride (YLF), respectively. These results are in satisfactory agreement with theoretical calculations based on the properties of Nd3+ free-ion wave functions. The difference between YAG and YLF, however, is not accounted for by the free-ion theory and suggests that the intermediate-state energies and wave functions are considerably host dependent. In addition, we conclude, based on our measurements, that rare-earth TPA will not contribute significantly to either losses or the nonlinear refractive index in typical laser media employing rare-earth ions.

  1. SODIUM FLUORIDE ALTERATION OF PROTEIN CONTENT VIS-À-VIS ELECTROPHORETIC PATTERN OF MUSCLE ESTERASES (E.C.3.1.1.1 IN POECILIA RETICULATA PETERS ON CHRONIC EXPOSURE

    Directory of Open Access Journals (Sweden)

    HITESH U. SHINGADIA AND **E.R. AGHARIA

    2014-12-01

    Full Text Available ABSTRACT: A progressive reduction in protein content observed in the muscle of fish in present study was both as a function of time as well as increase in the concentration of fluoride. During chronic exposure to sodium fluoride, the banding pattern of esterase diminished in the treated group of fish viz.  lowest (5.75 ppm, lower intermediate (7.18 ppm, higher intermediate (9.58 ppm and highest (14.37 ppm concentration of the 24 hrs. LC50 (115 ppm value when compared with the control group. SDS-PAGE and staining of the gel revealed that esterase in muscle of fish from control group resolved into six bands (lane-1. Exposure of fluoride to all the four concentrations showed significantly faint and diffused banding pattern of esterases and complete loss of esterase band-1 (Lane 2-5, probably due to chronic stress induced by fluoride. The esterase from band-1 might be sensitive to fluoride intoxication, thus completely vanished during chronic treatment. However in the higher intermediate (9.58 ppm and highest (14.37 ppm sodium fluoride treatment groups, sixth band of esterase (lane 4-5 was found to be very faintly visible on staining. Decrement in protein content & diminution of certain esterase bands in the muscle tissue of the treated group suggest soft tissue (non-skeletal fluorosis induced by sodium fluoride during chronic exposure period, probably could be due to inhibition of biosynthetic mechanism of proteins vis-à-vis esterases. The study of esterase in fish calls attention to sensitive indicator of the environmental pollutants and can be used as contrivance in study of environmental dilapidations. KEY WORDS: Protein, Esterase isozymes, Electrophoresis, Sodium fluoride, Poecilia reticulata.

  2. The Kinetics and Reproducibility of 18F-Sodium Fluoride for Oncology Using Current PET Camera Technology

    Science.gov (United States)

    Kurdziel, Karen A.; Shih, Joanna H.; Apolo, Andrea B.; Lindenberg, Liza; Mena, Esther; McKinney, Yolanda; Adler, Stephen S.; Turkbey, Baris; Dahut, William; Gulley, James L.; Madan, Ravi A.; Landgren, Ola; Choyke, Peter L.

    2012-01-01

    We evaluated the kinetics of 18F-sodium fluoride (NaF) and reassessed the recommended dose, optimal uptake period, and reproducibility using a current-generation PET/CT scanner. Methods In this prospective study, 73 patients (31 patients with multiple myeloma or myeloma precursor disease and 42 with prostate cancer) were injected with a mean administered dose of 141 MBq of 18F-NaF. Sixty patients underwent 3 sequential sessions of 3-dimensional PET/CT of the torso beginning ~15 min after 18F-NaF injection, followed by a whole-body 3-dimensional PET/CT at 2 h. The remaining 13 prostate cancer patients were imaged only at 2 and 3 h after injection. Twenty-one prostate cancer patients underwent repeat baseline studies (mean interval, 5.9 d) to evaluate reproducibility. Results The measured effective dose was 0.017 mSv/MBq, with the urinary bladder, osteogenic cells, and red marrow receiving the highest doses at 0.080, 0.077, and 0.028 mGy/MBq, respectively. Visual analysis showed that uptake in both normal and abnormal bone increased with time; however, the rate of increase decreased with time. A semiautomated workflow provided objective uptake parameters, including the mean standardized uptake value of all pixels within bone with SUVs greater than 10 and the average of the mean SUV of all malignant lesions identified by the algorithm. The values of these parameters for the images beginning at ~15 min and ~35 min were significantly different (0.3% change/minute). Differences between the later imaging time points were not significant (P 0.9) and relatively low critical percent change (the value above which a change can be considered real) for these parameters. The tumor-to-normal bone ratio, based on the SUVmax of identified malignant lesions, decreased with time; however, this difference was small, estimated at ~0.16%/min in the first hour. Conclusion 18F-NaF PET/CT images obtained with modest radiation exposures can result in highly reproducible imaging parameters

  3. Effect of sodium fluoride and stannous chloride associated with Nd:YAG laser irradiation on the progression of enamel erosion.

    Science.gov (United States)

    João-Souza, Samira Helena; Bezerra, Sávio José Cardoso; Borges, Alessandra Bühler; Aranha, Ana Cecília; Scaramucci, Tais

    2015-12-01

    This study evaluated the progression of enamel erosion after treatment with gels containing sodium fluoride (NaF; 9047 ppm F) and stannous chloride (SnCl2; 3000 ppm Sn), associated or not with Nd:YAG laser irradiation. Sixty enamel specimens were prepared from bovine incisors and protected by a tape, leaving an exposed surface area of 4 × 1 mm. The specimens were immersed in 1 % citric acid (pH = 2.3) for 10 min to create an initial erosion lesion. After, they were randomly divided into six groups: (C) control: gel without active ingredient; (F): NaF gel; (F + Sn): NaF + SnCl2 gel; (laser): Nd:YAG laser irradiation (0.5 W; 50 mJ; ∼41.66 J/cm(2); 10 Hz; 40 s); (F + laser): NaF gel + Nd:YAG; (F + Sn + laser): NaF + SnCl2 gel + Nd:YAG. All gels had pH = 4.5 and were applied for 1 min. Laser irradiation was performed after gel application. The specimens were then submitted to a 5-day erosion-remineralization cycling model using 1 % citric acid (pH = 2.3), six times per day. Enamel surface loss (SL) was analyzed by optical profilometry in the end of the cycling (in μm). Data were analyzed by one-way ANOVA and Holm-Sidak tests (alpha = 0.05). The control and the laser groups presented the highest enamel loss (means ± SD = 53.52 ± 3.65 and 53.30 ± 2.73, respectively), followed by F + Sn (44.76 ± 2.83). The groups F (36.76 ± 2.28), F + laser (36.25 ± 3.59), and F + Sn + laser (39.83 ± 4.62) showed the lowest enamel loss, with no significant difference among them (p > 0.05). In conclusion, NaF by itself or associated with SnCl2 and Nd:YAG laser was able to reduce enamel erosion progression. Nd:YAG laser alone did not show a protective effect.

  4. Final report on the safety assessment of aluminum silicate, calcium silicate, magnesium aluminum silicate, magnesium silicate, magnesium trisilicate, sodium magnesium silicate, zirconium silicate, attapulgite, bentonite, Fuller's earth, hectorite, kaolin, lithium magnesium silicate, lithium magnesium sodium silicate, montmorillonite, pyrophyllite, and zeolite.

    Science.gov (United States)

    Elmore, Amy R

    2003-01-01

    This report reviews the safety of Aluminum, Calcium, Lithium Magnesium, Lithium Magnesium Sodium, Magnesium Aluminum, Magnesium, Sodium Magnesium, and Zirconium Silicates, Magnesium Trisilicate, Attapulgite, Bentonite, Fuller's Earth, Hectorite, Kaolin, Montmorillonite, Pyrophyllite, and Zeolite as used in cosmetic formulations. The common aspect of all these claylike ingredients is that they contain silicon, oxygen, and one or more metals. Many silicates occur naturally and are mined; yet others are produced synthetically. Typical cosmetic uses of silicates include abrasive, opacifying agent, viscosity-increasing agent, anticaking agent, emulsion stabilizer, binder, and suspending agent. Clay silicates (silicates containing water in their structure) primarily function as adsorbents, opacifiers, and viscosity-increasing agents. Pyrophyllite is also used as a colorant. The International Agency for Research on Cancer has ruled Attapulgite fibers >5 microm as possibly carcinogenic to humans, but fibers mining and processing of Aluminum Silicate, Calcium Silicate, Zirconium Silicate, Fuller's Earth, Kaolin, Montmorillonite, Pyrophyllite, and Zeolite. The Cosmetic Ingredient Review (CIR. The Cosmetic Ingredient Review (CIR) Expert Panel concluded that the extensive pulmonary damage in humans was the result of direct occupational inhalation of the dusts and noted that lesions seen in animals were affected by particle size, fiber length, and concentration. The Panel considers that most of the formulations are not respirable and of the preparations that are respirable, the concentration of the ingredient is very low. Even so, the Panel considered that any spray containing these solids should be formulated to minimize their inhalation. With this admonition to the cosmetics industry, the CIR Expert Panel concluded that these ingredients are safe as currently used in cosmetic formulations. The Panel did note that the cosmetic ingredient, Talc, is a hydrated magnesium silicate

  5. iTRAQ-Based Proteomics Analysis of Serum Proteins in Wistar Rats Treated with Sodium Fluoride: Insight into the Potential Mechanism and Candidate Biomarkers of Fluorosis

    Science.gov (United States)

    Wei, Yan; Zeng, Beibei; Zhang, Hua; Chen, Cheng; Wu, Yanli; Wang, Nanlan; Wu, Yanqiu; Shen, Liming

    2016-01-01

    Fluorosis induced by exposure to high level fluoride is quite widespread in the world. The manifestations of fluorosis include dental mottling, bone damage, and impaired malfunction of soft tissues. However, the molecular mechanism of fluorosis has not been clarified until now. To explore the underlying mechanisms of fluorosis and screen out serum biomarkers, we carried out a quantitative proteomics study to identify differentially expressed serum proteins in Wistar rats treated with sodium fluoride (NaF) by using a proteomics approach of isobaric tagging for relative and absolute quantitation (iTRAQ). We fed Wistar rats drinking water that had 50, 150, and 250 mg/L of dissolved NaF for 24 weeks. For the experimental duration, each rat was given an examination of the lower incisors to check for the condition of dental fluorosis (DF). By the end of the treatment, fluoride ion concentration in serum and lower incisors were detected. The results showed that NaF treatment can induce rat fluorosis. By iTRAQ analysis, a total of 37 differentially expressed serum proteins were identified between NaF-treated and control rats. These proteins were further analyzed by bioinformatics, out of which two proteins were validated by enzyme-linked immunoadsorbent assays (ELISA). The major proteins were involved in complement and coagulation cascade, inflammatory response, complement activation, defense response, and wound response, suggesting that inflammation and immune reactions may play a key role in fluorosis pathogenesis. These proteins may contribute to the understanding of the mechanism of fluoride toxicity, and may serve as potential biomarkers for fluorosis. PMID:27690006

  6. iTRAQ-Based Proteomics Analysis of Serum Proteins in Wistar Rats Treated with Sodium Fluoride: Insight into the Potential Mechanism and Candidate Biomarkers of Fluorosis

    Directory of Open Access Journals (Sweden)

    Yan Wei

    2016-09-01

    Full Text Available Fluorosis induced by exposure to high level fluoride is quite widespread in the world. The manifestations of fluorosis include dental mottling, bone damage, and impaired malfunction of soft tissues. However, the molecular mechanism of fluorosis has not been clarified until now. To explore the underlying mechanisms of fluorosis and screen out serum biomarkers, we carried out a quantitative proteomics study to identify differentially expressed serum proteins in Wistar rats treated with sodium fluoride (NaF by using a proteomics approach of isobaric tagging for relative and absolute quantitation (iTRAQ. We fed Wistar rats drinking water that had 50, 150, and 250 mg/L of dissolved NaF for 24 weeks. For the experimental duration, each rat was given an examination of the lower incisors to check for the condition of dental fluorosis (DF. By the end of the treatment, fluoride ion concentration in serum and lower incisors were detected. The results showed that NaF treatment can induce rat fluorosis. By iTRAQ analysis, a total of 37 differentially expressed serum proteins were identified between NaF-treated and control rats. These proteins were further analyzed by bioinformatics, out of which two proteins were validated by enzyme-linked immunoadsorbent assays (ELISA. The major proteins were involved in complement and coagulation cascade, inflammatory response, complement activation, defense response, and wound response, suggesting that inflammation and immune reactions may play a key role in fluorosis pathogenesis. These proteins may contribute to the understanding of the mechanism of fluoride toxicity, and may serve as potential biomarkers for fluorosis.

  7. Influence of sodium silicate concentration on structural and tribological properties of microarc oxidation coatings on 2017A aluminum alloy substrate

    Energy Technology Data Exchange (ETDEWEB)

    Polat, Aytekin, E-mail: apolat@nigde.edu.t [Department of Mechanical Engineering, Nigde University, Nigde 51100 (Turkey); Makaraci, Murat [Department of Mechanical Engineering, Kocaeli University, Kocaeli (Turkey); Usta, Metin [Department of Materials Science and Engineering, Gebze Institute of Technology, Kocaeli (Turkey)

    2010-08-20

    In this paper, thick and hard oxide coatings resistant to wear were produced on 2017A-T6 Al alloy by the microarc oxidation (MAO) technique in an alkali electrolyte consisting of different sodium silicate concentrations (0-8 g/l). The coatings were characterized by means of optical microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD) and surface profilometry. Microhardness, scratch adhesion and pin-on-disk sliding wear tests were also performed to evaluate the tribological properties of the coatings. The influence of sodium silicate concentration on the structural and tribological properties of the MAO coatings was discussed. Results reveal that increasing sodium silicate concentration from 0 to 8 g/l in the electrolyte caused an increase in the electrolyte conductivity (from 7.71 to 18.1 mS/cm) and a decrease in positive final voltage (from 627 to 590 V) in the MAO process. In response to the increase in sodium silicate concentration, the thickness, surface roughness (R{sub a}) and critical load (L{sub c}) corresponding to adhesive failure of the coatings were increased simultaneously from 74 to 144 {mu}m, and 4.4 to 6.58 {mu}m, and 127.76 to 198.54 N, respectively. At the same time, the phase structure and composition of the coatings also varied by the participation of silicate ions in the reactions and their incorporation into the coating structure. Moreover, it was observed that the coating formed in the low sodium silicate concentration (4 g/l) had higher surface hardness (2020 HV) and improved wear resistance than the one (1800 HV) formed in the high sodium silicate concentration (8 g/l). The coatings produced in three different electrolytic solutions provided an excellent wear resistance and a load carrying capacity compared to the uncoated aluminum alloy.

  8. Fluoridation Basics

    Science.gov (United States)

    ... Page Basic Information About Fluoride Benefits: Strong Teeth History of Fluoride in Water Cost: Saves Money, Saves Teeth Fluoride in the Water Today The mineral fluoride occurs naturally on earth and is released from rocks into the soil, ...

  9. Electrochemical evaluation of sodium metabisulfite as environmentally friendly inhibitor for corrosion of aluminum alloy 6061 in a chloride solution

    Energy Technology Data Exchange (ETDEWEB)

    Zaid, B., E-mail: zaidbachir@yahoo.com [Département de métallurgie, Division de Technologie du Combustible, Centre de Recherche Nucléaire de Draria CRND, BP. 43 Draria, Alger (Algeria); Maddache, N.; Saidi, D. [Département de métallurgie, Division de Technologie du Combustible, Centre de Recherche Nucléaire de Draria CRND, BP. 43 Draria, Alger (Algeria); Souami, N. [Centre de Recherche Nucléaire d’Alger CRNA, 2 Bd. Frantz Fanon, Alger (Algeria); Bacha, N. [Département de Mécanique, Université SAAD Dahleb, Blida (Algeria); Si Ahmed, A. [Im2np, UMR 7334 CNRS, Aix-Marseille Université, 13397 Marseille Cedex 20 (France)

    2015-04-25

    Highlights: • Sodium metabisulfite acts as cathodic-type inhibitor. • The polarization resistance increases with the inhibitor concentration. • The pit nucleation rate decreases with increasing inhibitor concentration. • The current rise linked to pit propagation drops as inhibitor content increases. • The reactions involved in the inhibition actions are pointed out. - Abstract: Inhibition properties of sodium metabisulfite (Na{sub 2}S{sub 2}O{sub 5}) on pitting corrosion of 6061 aluminum alloy, in 5 × 10{sup −2} M NaCl solution of pH near 7.2 at 298 K, are characterized using open circuit potential, polarization resistance, cyclic and chrono-amperometric polarization measurements. In addition, scanning electron microscopy coupled with energy dispersive spectroscopy and X-ray photoelectrons are employed. Sodium metabisulfite, which is well compatible with environmental requirements, seems to act as a cathodic-type corrosion inhibitor. The passivation range and the polarization resistance increase with Na{sub 2}S{sub 2}O{sub 5} concentration. The inhibition effects are also reflected through the substantial reduction of both the rate of pit nucleation and the current rise characterizing the pit propagation progress. The SEM–EDS and XPS analyses reveal the formation of a passive film, which contains sulfur atoms.

  10. An investigation of the pathophysiological mechanisms of hydrofluoric acid intoxication in rats and pigs. Interim report concerning the results of phase 2.1: The effect of sodium fluoride infusion on the plasma concentrations of lactate and magnesium

    NARCIS (Netherlands)

    Boink ABTJ; de Wildt DJ; de Jong Y; de Groot G; Vaessen HAMG; Meulenbelt J; van Dijk A; Vosmeer H

    1990-01-01

    From a previous study it was concluded that intravenous infusion of sodium fluoride (NaF) in rats is a suitable model to study the toxicity of hydrofluoric acid. In this supplementary study we investigated the effect of intravenous infusion of a high and low dose of NaF (120 and 25 mg.kg -1.hr -1

  11. Interaction of DNA-lesions induced by sodium fluoride and radiation and its influence in apoptotic induction in cancer cell lines

    Directory of Open Access Journals (Sweden)

    Santosh Podder

    2015-01-01

    Full Text Available Fluoride is an essential trace element but also an environmental contaminant with major sources of exposure being drinking water, food and pesticides. Previous studies showed that sodium fluoride (NaF at 5 mM or more is required to induce apoptosis and chromosome aberrations and proposed that DNA damage and apoptosis play an important role in toxicity of excessive fluoride. The aim of this study is directed to understand the nature of DNA-lesions induced by NaF by allowing its interaction with radiation induced DNA-lesions. NaF 5 mM was used after observing inability to induce DNA damages and apoptosis by single exposure with 50 μM or 1 mM NaF. Co-exposure to NaF and radiation significantly increased the frequency of aberrant metaphases and exchange aberrations in human lymphocytes and arrested the cells in G1 stage instead of apoptotic death. Flow cytometric analysis, DNA fragmentation and PARP-cleavage analysis clearly indicated that 5 mM NaF together with radiation (1 Gy induced apoptosis in both U87 and K562 cells due to down regulation of expression of anti-apoptotic proteins, like Bcl2 in U87 and inhibitors of apoptotic proteins like survivin and cIAP in K562 cells. This study herein suggested that single exposure with extremely low concentration of NaF unable to induce DNA lesions whereas higher concentration induced DNA lesions interact with the radiation-induced DNA lesions. Both are probably repaired rapidly thus showed increased interactive effect. Coexposure to NaF and radiation induces more apoptosis in cancer cell lines which could be due to increased exchange aberrations through lesions interaction and downregulating anti-apoptotic genes.

  12. Kagomé lattices as cathode: Effect of particle size and fluoride substitution on electrochemical lithium insertion in sodium- and ammonium Jarosites

    Science.gov (United States)

    Sandineni, Prashanth; Yaghoobnejad Asl, Hooman; Choudhury, Amitava

    2016-10-01

    Highly crystalline sodium and ammonium Jarosites, NaFe3(SO4)2(OH)6 and NH4Fe3(SO4)2(OH)6, have been synthesized employing hydrothermal synthesis routes. The structures consist of anionic layers of vertex-sharing FeO6 octahedra and SO4 tetrahedral units with interlayer space occupied by Na and ammonium ions, respectively. The corner-sharing FeO6 octahedral units form six and three rings similar to hexagonal tungsten bronze sheets also known as kagomé lattice. These sodium and ammonium Jarosites are thermally stable up to 400 °C and undergo facile electrochemical lithium insertion through the reduction of Fe3+ to Fe2+. Galvanostatic charge-discharge indicates that up to 2.25 and 2 lithium ions per formula unit can be inserted at an average voltage of 2.49 and 2.26 V to the sodium and the ammonium Jarosites, respectively, under slow discharge rate of C/50. The cycle-life and experimental achievable capacity show strong dependence on particle sizes and synthesis conditions. A small amount of fluoride substitution improves both achievable capacity and average voltage.

  13. Sodium fluoride affects zebrafish behaviour and alters mRNA expressions of biomarker genes in the brain: Role of Nrf2/Keap1.

    Science.gov (United States)

    Mukhopadhyay, Debdip; Priya, Pooja; Chattopadhyay, Ansuman

    2015-09-01

    Sodium fluoride (NaF), used as pesticides and for industrial purposes are deposited in the water bodies and therefore affects its biota. Zebrafish exposed to NaF in laboratory condition showed hyperactivity and frequent surfacing activity, somersaulting and vertical swimming pattern as compared to the control group. Reactive oxygen species level was elevated and glutathione level was depleted along with increased malondialdehyde content in the brain. Levels of glutathione-s-transferase (GST), catalase (CAT) and superoxide dismutase were also elevated in the treatment groups. Expression of mRNA of nuclear factor erythroid 2 related factor 2 (Nrf2) and its inhibitor Kelch-like ECH-associated protein 1 (Keap1) during stress condition were observed along with Gst, Cat, NADPH: quinone oxidoreductase 1(Nqo1) and p38. Except Keap1, all other genes exhibited elevated expression. Nrf2/Keap1 proteins had similar expression pattern as their corresponding mRNA. The findings in this study might help to understand the molecular mechanism of fluoride induced neurotoxicity in fish.

  14. Relationships of human plasma fluoride and bone fluoride to age

    Energy Technology Data Exchange (ETDEWEB)

    Parkins, F.M.; Tinanoff, N.; Moutinho, M.; Anstey, M.B.; Waziri, M.H.

    1976-04-01

    There is evidence that fluoride levels in plasma correlate with the fluoride content in bones. The authors determined whether or not fluoride in plasma and bones might correlate with age. In 41 in-patients at the University Hospital, Iowa City, 36 of whom had been residing in fluoridated communities plasma fluoride was determined in the fasting stage by the fluoride ion selective electrode. The teeth of these children were compared with those of a neighboring city where the natural fluoride content in drinking water was 0.1 ppm. For the second sampling 42 months following the beginning of the program only 10 and 11 year old children - who had been 6 and 7 years old at the beginning of the experiment - were selected. Twenty-five boys and girls in each group were compared with a similar group of children as controls. After 28 months (approximately 33 rinsing with sodium fluoride solution) the DMF index in the fluoride-treated children was 18.4% less than in the controls. In the second group among 10 and 11 year old children after 42 months with 55 rinsings the difference was 35.0%. The author acknowledged that factors other than applications of sodium fluoride may have contributed to the prevention of caries in the fluoride-treated groups.

  15. Effect of Phosphate, Fluoride, and Nitrate on Gibbsite Dissolution Rate and Solubility

    Energy Technology Data Exchange (ETDEWEB)

    Herting, Daniel L. [Washington River Protection Solutions LLC (United States)

    2014-01-29

    Laboratory tests have been completed with simulated tank waste samples to investigate the effects of phosphate, fluoride, and nitrate on the dissolution rate and equilibrium solubility of gibbsite in sodium hydroxide solution at 22 and 40{degrees}C. Results are compared to relevant literature data and to computer model predictions. The presence of sodium nitrate (3 M) caused a reduction in the rate of gibbsite dissolution in NaOH, but a modest increase in the equilibrium solubility of aluminum. The increase in solubility was not as large, though, as the increase predicted by the computer model. The presence of phosphate, either as sodium phosphate or sodium fluoride phosphate, had a negligible effect on the rate of gibbsite dissolution, but caused a slight increase in aluminum solubility. The magnitude of the increased solubility, relative to the increase caused by sodium nitrate, suggests that the increase is due to ionic strength (or water activity) effects, rather than being associated with the specific ion involved. The computer model predicted that phosphate would cause a slight decrease in aluminum solubility, suggesting some Al-PO4 interaction. No evidence was found of such an interaction.

  16. [Studies on the mechanism of action of vascular spasmolytics. 3. Effect of nitroprusside sodium, nitroglycerin, prenylamine and verapamil on the fluoride-induced contracture of the isolated coronary artery].

    Science.gov (United States)

    Fermum, R; Meisel, P; Klinner, U

    1977-01-01

    On isolated coronary arteries of cattle, nitroprusside-sodium, nitroglycerol, prenylamine, and verapamil were studied for their spasmolytic effects on a contracture induced by fluoride ions. With this contracture model, which is independent of extracellular calcium, nitroprosside-sodium and nitroglycerol showed strong spasmolytic action. Verapamil proved ineffective, and the effectiveness of prenylamine was strongly reduced. The results lend support to earlier findings suggesting that nitroglycerol and nitroprusside-sodium are endowed with a relaxation mechanism different from that of verapamil and analogously acting compounds.

  17. The effectiveness of the biannual application of silver nitrate solution followed by sodium fluoride varnish in arresting early childhood caries in preschool children: study protocol for a randomised controlled trial

    OpenAIRE

    Chu, Chun-Hung; Gao, Sherry Shiqian; Li, Samantha KY; Wong, May CM; Lo, Edward CM.

    2015-01-01

    Background The application of 38 % silver diamine fluoride (SDF) has been shown to be effective in arresting early childhood caries (ECC). Since SDF is not available in certain countries, some dentists use adjunctive application of 25 % silver nitrate (AgNO3) and 5 % sodium fluoride (NaF) to arrest ECC. This randomised controlled trial will systematically compare the efficacy of a 25 % AgNO3 solution followed by 5 % NaF varnish with that of a 38 % SDF solution in arresting ECC when applied at...

  18. Industrial fluoride pollution: chronic fluoride poisoning in Cornwall Island cattle

    Energy Technology Data Exchange (ETDEWEB)

    Krook, L.; Maylin, G.A.

    1979-04-01

    An aluminum plant on the south bank of the St. Lawrence River, southwest of Cornwall Island, Ontario, Canada, has emitted 0.816 metric tons of fluoride daily since 1973. Considerably higher amounts were emitted from 1959 to 1973. The plant was designated as the major source of fluoride emissions impacting on Cornwall Island. Cattle located on this island showed signs of chronic fluoride poisoning. This poisoning was manifested clinically by stunted growth and dental fluorosis to a degree of severe interference with drinking and mastication. This Cornwall Island herds study indicates that the established tolerance level of fluoride for performance of dairy and beef cattle is not valid since the tolerance level was set based on experiments with healthy calves which were exposed to dietary fluoride from 3 to 4 months of age and not on cattle which were chronically exposed to fluoride from conception to death. 56 references.

  19. 氟铝联合中毒对小鼠骨代谢生物标志物的影响%Joint effects of fluoride and aluminum on biomarkers of bone metabolism in mice

    Institute of Scientific and Technical Information of China (English)

    杨莉萍; 王克跃; 石修权; 李红

    2008-01-01

    Objective To explore the interaction characters of fluoride and aluminum by analyzing the changes of bone metabolism in mice. Methods Kunming mice were randomly divided into nine groups according to the factorial experiment, design of two factors and three levels. The animals in different groups were fed with various doses of fluoride(NaF, 0,50,150 mg/L) and/or aluminum(AlCl3, 0,200,600 mg/L) in drinking water for 24 weeks. Serum calcium, phosphor, magnesium, alkaline phosphatase, osteoealine, parathyroid, and urinary calcium and phosphor were tested. Results We found interaetians of fluoride and aluminum with serum calcium, osteoealine and urine calcium(F=17.370,4.399,9.448, P<0.01), but not with serum phosphor, magnesium, alkaline phosphatase, parathyroid or urinary phospbor(F=0.416,0.415,1.921,1.362, 1.630, P 0.05). The serum levels of calcium and osteoealine in high fluoride group were (1.13±0.27)mmol/L and (6.56±5.74)μg/L, respectively, which were lower than in the control group[ (1.82±0.37)mmol/L and (23.45±15.40)laeJL, respectively], but the levels were elevated to (1.76±0.36)mmol/L and (10.57±4.28)μg/L when high fluoride was combined with low aluminum, and further elevated to (2.10±0.51)mmol/L and (15.73±3.15)μg/L when high fluoride was combined with high aluminum. The urinary calcium level in low fluoride group [ (6.24±2.61)retool/retool Cr] was higher than that in the control group[ (3.12±2.04)retool/retool Cr], but it was decreased in low fluoride and aluminum groups[ (0.81±0.44), (1.23± 0.41)mmol/mmoi Cr, respectively]. On the other hand, the levels of serum ealeium and osteocaline in high aluminum group were (1.07±0.68)mmol/L and (7.21±5.22)μg/L, elevated to (1.47±0.18)mmol/L and (10.98±4.35) μg/L when low fluoride was combined wth high aluminum, and further elevated to (2.10±0.51)mmol/L and (15.73± 3.15)μg/L when high fluoride was.combined with high aluminum, respectively, and the combined effects showed the same trend of

  20. The optical constants of several atmospheric aerosol species - Ammonium sulfate, aluminum oxide, and sodium chloride

    Science.gov (United States)

    Toon, O. B.; Pollack, J. B.; Khare, B. N.

    1976-01-01

    An investigation is conducted of problems which are related to a use of measured optical constants in the simulation of the optical constants of real atmospheric aerosols. The techniques of measuring optical constants are discussed, taking into account transmission measurements through homogeneous and inhomogeneous materials, the immersion of a material in a liquid of a known refractive index, the consideration of the minimum deviation angle of prism measurement, the interference of multiply reflected light, reflectivity measurements, and aspects of mathematical analysis. Graphs show the real and the imaginary part of the refractive index as a function of wavelength for aluminum oxide, NaCl, and ammonium sulfate. Tables are provided for the dispersion parameters and the optical constants.

  1. Fluoride and aluminum in teas and tea-based beverages Flúor e alumínio em chás e bebidas à base de chás

    Directory of Open Access Journals (Sweden)

    Mitsue Fujimaki Hayacibara

    2004-02-01

    Full Text Available OBJECTIVE: To evaluate fluoride and aluminum concentration in herbal, black, ready-to-drink, and imported teas available in Brazil considering the risks fluoride and aluminum pose to oral and general health, respectively. METHODS: One-hundred and seventy-seven samples of herbal and black tea, 11 types of imported tea and 21 samples of ready-to-drink tea were divided into four groups: I-herbal tea; II-Brazilian black tea (Camellia sinensis; III-imported tea (Camellia sinensis; IV-ready-to-drink tea-based beverages. Fluoride and aluminum were analyzed using ion-selective electrode and atomic absorption, respectively. RESULTS: Fluoride and aluminum levels in herbal teas were very low, but high amounts were found in black and ready-to-drink teas. Aluminum found in all samples analyzed can be considered safe to general health. However, considering 0.07 mg F/kg/day as the upper limit of fluoride intake with regard to undesirable dental fluorosis, some teas exceed the daily intake limit for children. CONCLUSIONS: Brazilian and imported teas made from Camellia sinensis as well as some tea-based beverages are sources of significant amounts of fluoride, and their intake may increase the risk of developing dental fluorosis.OBJETIVO: Avaliar as concentrações de flúor e alumínio em chás brasileiros de ervas, preto e bebidas a base de chá, como em chás preto importados considerando seus riscos para, respectivamente, a saúde oral e geral. MÉTODOS: Foram analisadas 177 amostras de chá de ervas e chá preto, 11 tipos de chá preto importados e 21 amostras de bebidas à base de chá. Flúor e alumínio foram determinados após infusão dos chás de ervas e pretos. As determinações de flúor e alumínio foram feitas por eletrodo específico e absorção atômica, respectivamente. RESULTADOS: A quantidade de flúor e alumínio encontrada nos chás de erva foi muito baixa, mas foi alta nos chás preto e nas bebidas à base de chá. A quantidade de alum

  2. ALUMINUM REMOVAL AND SODIUM HYDROXIDE REGENERATION FROM HANFORD TANK WASTE BY LITHIUM HYDROTALCITE PRECIPITATION SUMMARY OF PRIOR LAB-SCALE TESTING

    Energy Technology Data Exchange (ETDEWEB)

    SAMS TL; GUILLOT S

    2011-01-27

    Scoping laboratory scale tests were performed at the Chemical Engineering Department of the Georgia Institute of Technology (Georgia Tech), and the Hanford 222-S Laboratory, involving double-shell tank (DST) and single-shell tank (SST) Hanford waste simulants. These tests established the viability of the Lithium Hydrotalcite precipitation process as a solution to remove aluminum and recycle sodium hydroxide from the Hanford tank waste, and set the basis of a validation test campaign to demonstrate a Technology Readiness Level of 3.

  3. Er:YAG激光与氟化钠治疗牙本质过敏症的疗效观察%Observation on the Clinical Effect of Er: YAG Laser Irradiation and Sodium Fluoride in Treating Dentin Hypersensitivity

    Institute of Scientific and Technical Information of China (English)

    叶丽君; 邓蔓菁; 刘鲁川; 李向杰; 安建平; 董正谋

    2013-01-01

    Objective: To observe the clinical curative effect of dentine hypersensitivity being locally treated by Er: YAG laser irradiation and sodium fluoride. Methods: 85 patients with dentine hypersensitivity were collected and randomly divided into four groups : A (laser treatment) , B (sodium fluoride treatment), C (combination treatment of laser and sodium fluoride) and D (blank controll), following the VAS(visual analogue scale)score to analyze the clinical curative effect of different treatment on dentine hypersensitivity. Results: The VAS scores in observation period have a decreasing trend. Comparing A, B and C group with D group, there have statistical differences (Psodium fluoride to treat dentine hypersensitivity locally has significantly clinical curative effect.%目的:观察Er:YAG激光照射和氟化钠局部治疗牙本质过敏的临床疗效.方法:临床收集85名牙本质过敏的患者,随机分为A(激光治疗)、B(氟化钠治疗)、C(激光联合氟化钠治疗)和D(空白对照)4组,利用直观疼痛标尺法VAS(visual analogue scale)分析其疗效.结果:在观察期间实验组VAS评分均有降低的趋势,A、B、C和D组相比有统计学差异(P<0.05);C和A、B组相比有统计学差异(P<0.05).结论:Er:YAG激光照射联合氟化钠局部治疗牙本质过敏临床疗效显著.

  4. Entropic nature of the adsorption of sodium dodecylbenzenesulfonate on nanoparticles of aluminum and iron oxides in aqueous medium

    Science.gov (United States)

    Mansurov, R. R.; Safronov, A. P.; Lakiza, N. V.

    2016-06-01

    The adsorption of anionic surfactant sodium dodecylbenzenesulfonate (SDBS) from aqueous solution on the hydrophilic surfaces of aluminum oxide and iron oxide nanoparticles is studied via UV spectrophotometry, electrophoretic light scattering, and isothermal microcalorimetry. It is shown that the isotherms of the adsorption of SDBS on the surfaces of both oxides in the area of concentrations up to 0.6 mmol/L is linear. It is found that the positive zeta potential of the surfaces of the particles falls to zero and shifts toward the range of negative values due to adsorption. The adsorption of SDBS is characterized by positive enthalpy values over the investigated range of concentrations, while the loss of energy during adsorption indicates it is of an entropic nature. It is concluded that the probable cause of the increase in entropy is the dehydration of SDBS molecules during on surface adsorption. The obtained results are discussed in terms of the formation of hemimicelles of surfactant on the hydrophilic surfaces of metal oxide nanoparticles in an aqueous medium.

  5. The effect of core and lanthanide ion dopants in sodium fluoride-based nanocrystals on phagocytic activity of human blood leukocytes

    Science.gov (United States)

    Sojka, Bartlomiej; Liskova, Aurelia; Kuricova, Miroslava; Banski, Mateusz; Misiewicz, Jan; Dusinska, Maria; Horvathova, Mira; Ilavska, Silvia; Szabova, Michaela; Rollerova, Eva; Podhorodecki, Artur; Tulinska, Jana

    2017-02-01

    Sodium fluoride-based β-NaLnF4 nanoparticles (NPs) doped with lanthanide ions are promising materials for application as luminescent markers in bio-imaging. In this work, the effect of NPs doped with yttrium (Y), gadolinium (Gd), europium (Eu), thulium (Tm), ytterbium (Yb) and terbium (Tb) ions on phagocytic activity of monocytes and granulocytes and the respiratory burst was examined. The surface functionalization of <10-nm NPs was performed according to our variation of patent pending ligand exchange method that resulted in meso-2,3-dimercaptosuccinic acid (DMSA) molecules on their surface. Y-core-based NCs were doped with Eu ions, which enabled them to be excited with UV light wavelengths. Cultures of human peripheral blood ( n = 8) were in vitro treated with five different concentrations of eight NPs for 24 h. In summary, neither type of nanoparticles is found toxic with respect to conducted test; however, some cause toxic effects (they have statistically significant deviations compared to reference) in some selected doses tested. Both core types of NPs (Y-core and Gd-core) impaired the phagocytic activity of monocytes the strongest, having minimal or none whatsoever influence on granulocytes and respiratory burst of phagocytic cells. The lowest toxicity was observed in Gd-core, Yb, Tm dopants and near-infrared nanoparticles. Clear dose-dependent effect of NPs on phagocytic activity of leukocytes and respiratory burst of cells was observed for limited number of samples.

  6. F-8 sodium fluoride position emission tomography/computed tomography for detection of thyroid cancer bone metastasis compared with bone scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyun Jong; Lee, Won Woo; Park, So Yeon; Kim, Sang Eun [Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2016-04-15

    The aim of the study was to compare the diagnostic performances of F-18 sodium fluoride positron emission tomography/computed tomography (bone PET/CT) and bone scintigraphy (BS) for the detection of thyroid cancer bone metastasis. We retrospectively enrolled 6 thyroid cancer patients (age = 44.7 ± 9.8 years, M:F = 1:5, papillary:follicular = 2:4) with suspected bone metastatic lesions in the whole body iodine scintigraphy or BS, who subsequently underwent bone PET/CT. Pathologic diagnosis was conducted for 4 lesions of 4 patients. Of the 17 suspected bone lesions, 10 were metastatic and 7 benign. Compared to BS, bone PET/CT exhibited superior sensitivity (10/10 = 100% vs. 2/10 = 20%, p = 0.008), and accuracy (14/17 = 82.4% vs. 7/17 = 41.2%, p < 0.025). The specificity (4/7 = 57.1%) of bone PET/CT was not significantly different from that of BS (5/7 = 71.4%, p > 0.05). Bone PET/CT may be more sensitive and accurate than BS for the detection of thyroid cancer bone metastasis.

  7. In vivo protective effects of gallic acid isolated from Peltiphyllum peltatum against sodium fluoride-induced oxidative stress in rat erythrocytes.

    Science.gov (United States)

    Nabavi, Seyed Fazel; Habtemariam, Solomon; Sureda, Antoni; Hajizadeh Moghaddam, Akbar; Daglia, Maria; Nabavi, Seyed Mohammad

    2013-12-01

    Gallic acid has been identified as an antioxidant component of the edible and medicinal plant Peltiphyllum peltatum. The present study examined its potential protective role against sodium fluoride (NaF)-induced oxidative stress in rat erythrocytes. Oxidative stress was induced by NaF administration through drinking water (1030.675 mg m(-3) for one week). Gallic acid at 10 mg kg(-1) and 20 mg kg(-1) and vitamin C for positive controls (10 mg kg(-1)) were administered daily intraperitoneally for one week prior to NaF administration. Thiobarbituric acid reactive substances, antioxidant enzyme activities (superoxide dismutase and catalase), and the level of reduced glutathione were evaluated in rat erythrocytes. Lipid peroxidation in NaF-exposed rats significantly increased (by 88.8%) when compared to the control group (pgallic acid suppressed lipid peroxidation in erythrocytes in a dose-dependent manner. Catalase and superoxide dismutase enzyme activities and glutathione levels were reduced by NaF intoxication by 54.4%, 63.69%, and 42% (pgallic acid or vitamin C significantly attenuated the deleterious effects. Gallic acid isolated from Peltiphyllum peltatum and vitamin C mitigated the NaF-induced oxidative stress in rat erythrocytes.

  8. Evaluation of a mixture of zinc oxide, calcium hydroxide, and sodium fluoride as a new root canal filling material for primary teeth

    Directory of Open Access Journals (Sweden)

    Chawla H

    2008-06-01

    Full Text Available Endodontic treatment was performed on 25 pulpally involved mandibular primary molars in 4 to 9-year-old children; the root canals were obturated with a new root canal filling material consisting of a mixture of calcium hydroxide, zinc oxide, and 10% sodium fluoride solution, using hand-operated lentulo-spirals. All cases were evaluated clinically every 3 months and also radiographically every 6 months to assess the success of the treatment; we also examined the resorption of the root canal filling material from the root canals and the status of overpushed material, if any, as the tooth resorbed with the passage of time. At 6 months, endodontic treatment in 2 of the 25 teeth had failed and one tooth had exfoliated; the remaining 22 teeth were without any signs or symptoms. At the end of 2 years, 14 teeth could be evaluated; out of these 12 had physiologically exfoliated. It was observed that the rate of resorption of this new root canal obturating mixture was quite similar to the rate of physiologic root resorption in primary teeth. In three cases, where there was an overpush of the mixture, a gradual partial resorption was noted.

  9. The missing hydrate AlF3·6H2Odbnd [Al(H2O)6]F3: Ionothermal synthesis, crystal structure and characterization of aluminum fluoride hexahydrate

    Science.gov (United States)

    Wang, Guangmei; Mudring, Anja-Verena

    2016-11-01

    AlF3 is a strong Lewis acid and several hydrates of it are known, namely the monohydrate, the trihydrate (of which two polymorphs have been described) and the nonohydrate, which forms in the abundance of water, as well as a more complex fluoride of composition Al0.82□0.18F2.46(H2O)0.54 whose structure has been related to the ReO3 type. The monohydrate features edge connected [AlF6] octahedra, in the tri- and nonahydrate mixed F/O coordination of aluminum is observed. Here we report on a new aluminium fluoride hydrate, AlF3·6H2O, which could be obtained via ionothermal synthesis in the ionic liquid n-hexyl-pyridinium tetrafluoroborate. The ionic liquid serves in the synthesis of AlF3·6H2O as the reaction partner (fluoride source) and solvent. Overmore it controls the water activity allowing access to the missing AlF3·6H2O. Single-crystal X-ray diffraction analysis of AlF3·6H2O shows that it crystallizes in the anti-Li3Bi-type of structure according to F3[Al(H2O)6] (Fm-3m, a = 893.1(2) pm, Z = 4) featuring hexaaqua aluminium(III) cations and isolated fluoride anions. The compound was further characterized by powder X-ray diffraction, TG/DTA, IR analyses.

  10. Pharmacological and toxicological effects of co-exposure of human gingival fibroblasts to silver nanoparticles and sodium fluoride

    Science.gov (United States)

    Inkielewicz-Stepniak, Iwona; Santos-Martinez, Maria Jose; Medina, Carlos; Radomski, Marek W

    2014-01-01

    Background Silver nanoparticles (AgNPs) and fluoride (F) are pharmacological agents widely used in oral medicine and dental practice due to their anti-microbial/anti-cavity properties. However, risks associated with the co-exposure of local cells and tissues to these xenobiotics are not clear. Therefore, we have evaluated the effects of AgNPs and F co-exposure on human gingival fibroblast cells. Methods Human gingival fibroblast cells (CRL-2014) were exposed to AgNPs and/or F at different concentrations for up to 24 hours. Cellular uptake of AgNPs was examined by transmission electron microscopy. Downstream inflammatory effects and oxidative stress were measured by real-time quantitative polymerase chain reaction (PCR) and reactive oxygen species (ROS) generation. Cytotoxicity and apoptosis were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and real-time quantitative PCR and flow cytometry, respectively. Finally, the involvement of mitogen-activated protein kinases (MAPK) was studied using Western blot. Results We found that AgNPs penetrated the cell membrane and localized inside the mitochondria. Co-incubation experiments resulted in increased oxidative stress, inflammation, and apoptosis. In addition, we found that co-exposure to both xenobiotics phosphorylated MAPK, particularly p42/44 MAPK. Conclusion A combined exposure of human fibroblasts to AgNPs and F results in increased cellular damage. Further studies are needed in order to evaluate pharmacological and potentially toxicological effects of AgNPs and F on oral health. PMID:24729703

  11. Enabling aqueous binders for lithium battery cathodes - Carbon coating of aluminum current collector

    Science.gov (United States)

    Doberdò, Italo; Löffler, Nicholas; Laszczynski, Nina; Cericola, Dario; Penazzi, Nerino; Bodoardo, Silvia; Kim, Guk-Tae; Passerini, Stefano

    2014-02-01

    In this manuscript a novel approach to enable aqueous binders for lithium ion battery (LIB) cathodes is reported. Producing LiNi1/3Mn1/3Co1/3O2 (NMC) electrodes using sodium-carboxymethylcellulose (CMC) as a binder and water as a solvent, in fact, results in serious aluminum corrosion during electrode manufacturing due to the high pH of the slurry. In order to prevent the direct contact of the corrosive slurry with aluminum foil, the latter is first coated with a thin carbon layer. The CMC-based electrodes formed on carbon coated aluminum foil show enhanced performance than those made using unprotected aluminum instead. In particular, electrodes using protected aluminum foil are able to deliver a capacity of 126 mAh g-1 at 1C rate, which is rather close to that delivered by polyvinylidene-di-fluoride (PVdF)-based electrode having the same composition.

  12. Effects of cimetidine on adenylate cyclase activity of guinea pig gastric mucosa stimulated by histamine, sodium fluoride and 5'-guanylylimidodiphosphate.

    Science.gov (United States)

    Anttila, P; Westermann, E

    1976-08-01

    Cimetidine, a recently developed histamine H2-receptor blocking agent has been shown to be a potent inhibitor of histamine-stimulated gastric acid secretion in rat, cat, dog and man. To study the mode of action of cimetidine the modification of stimulatory effects of histamine, sodium flouride and 5'-guanylylimidodiphosphate by cimetidine on the adenylate cyclase activity of guinea pig gastric mucosa was studied. The effect of cimetidine was also compared to that of metiamide, an older histamine H2-receptor antagonist. The effect of cimetidine was qualitatively similar to that of metiamide, i.e. a selective blockade of histamine H2-receptors. Quantitatively cimetidine was about 10-fold more potent than metiamide.

  13. Hydrophobic sodium fluoride-based nanocrystals doped with lanthanide ions: assessment of in vitro toxicity to human blood lymphocytes and phagocytes.

    Science.gov (United States)

    Sojka, Bartlomiej; Kuricova, Miroslava; Liskova, Aurelia; Bartusova, Maria; Banski, Mateusz; Misiewicz, Jan; Dusinska, Maria; Horvathova, Mira; Jahnova, Eva; Ilavska, Silvia; Szabova, Michaela; Rollerova, Eva; Podhorodecki, Artur; Tulinska, Jana

    2014-11-01

    In vitro immunotoxicity of hydrophobic sodium fluoride-based nanocrystals (NCs) doped with lanthanide ions was examined in this study. Although there is already a significant amount of optical and structural data on NaYF4 NCs, data on safety assessment are missing. Therefore, peripheral whole blood from human volunteers was used to evaluate the effect of 25 and 30 nm hydrophobic NaYF4 NCs dissolved in cyclohexane (CH) on lymphocytes, and of 10 nm NaYF4 NCs on phagocytes. In the concentration range 0.12-75 µg cm(-2) (0.17-106 µg ml(-1) ), both 25 and 30nm NaYF4 NCs did not induce cytotoxicity when measured as incorporation of [(3) H]-thymidine into DNA. Assessment of lymphocyte function showed significant suppression of the proliferative activity of T-lymphocytes and T-dependent B-cell response in peripheral blood cultures (n = 7) stimulated in vitro with mitogens phytohemagglutinin (PHA) and pokeweed (PWM) (PHA > PWM). No clear dose-response effect was observed. Phagocytic activity and respiratory burst of leukocytes (n = 5-8) were generally less affected. A dose-dependent suppression of phagocytic activity of granulocytes in cultures treated with 25 nm NCs was observed (vs. medium control). A decrease in phagocytic activity of monocytes was found in cells exposed to higher doses of 10 and 30 nm NCs. The respiratory burst of phagocytes was significantly decreased by exposure to the middle dose of 30 nm NCs only. In conclusion, our results demonstrate immunotoxic effects of hydrophobic NaYF4 NCs doped with lanthanide ions to lymphocytes and to lesser extent to phagocytes. Further research needs to be done, particularly faze transfer of hydrophobic NCs to hydrophilic ones, to eliminate the solvent effect.

  14. Synthesis, quality control and dosimetry of the radiopharmaceutical 18F-sodium fluoride produced at the Center for Development of Nuclear Technology - CDTN

    Energy Technology Data Exchange (ETDEWEB)

    Silveira, Marina Bicalho; Soares, Marcella Araugio; Valente, Eduardo Sarmento; Waquil, Samira Soares; Santos, Raquel Gouvea dos; Silva, Juliana Batista da, E-mail: silvajb@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Serv. de Aplicacao das Radiacoes na Saude; Ferreira, Andrea Vidal [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Serv. de Reator e Irradiacoes

    2010-07-15

    {sup 18}F-Sodium fluoride (Na{sup 18}F) is a radiopharmaceutical used for diagnosis in nuclear medicine by positron emission tomography (PET) imaging. Bone scintigraphy is normally performed using {sup 99m}Tc- MDP. However, {sup 18}F PET scans promise high quality imaging with increased resolution and improved sensitivity and specificity. In order to make available a tool for more specific studies of tumors and non oncological diseases of bone tissue, the UPPR/CDTN team undertook the production and quality control of Na{sup 18}F injectable solution with the physical-chemical, microbiological and biological characteristics recommended in the U.S. Pharmacopeia. Na{sup 18}F radiochemical purity was 96.7 {+-} 1.3 %, with Rf= 0.026 {+-} 0.006. The product presented a pH of 5.3 {+-} 0.6, half life of 109.0 {+-} 0.8 minutes, endotoxin limit < 5.0 EU.mL{sup -1} and no microbial contaminants. The biodistribution of Na{sup 18}F was similar to that described in the literature, with a clearance of 0.19 mL.min{sup -1} and distribution volume of 18.76 mL. The highest bone concentration (5.0 {+-} 0.5 %ID.g{sup -1}) was observed 20 minutes after injection. Na{sup 18}F produced at the UPPR presented all the quality assurance requirements of the U.S. Pharmacopeia and can be safely used for clinical bone imaging. (author)

  15. Are Tubes Containing Sodium Fluoride Still Needed for the Measurement of Blood Glucose in Hospital Laboratory Practice?

    Directory of Open Access Journals (Sweden)

    Amira Al-Kharusi

    2014-11-01

    Full Text Available Objectives: To compare glucose values obtained using sodium flouride (NaF tubes and serum separation tubes (SST in a tertiary care hospital laboratory setting.  Methods: This study was conducted at the Clinical Biochemistry Laboratory, Royal Hospital, Oman. During the study period (1 September–30 November 2013, 50 pairs (one NaF tube and one SST of patient’s blood specimens were randomly collected. Following separation of plasma (NaF tubes and serum (SST, glucose concentrations were measured by hexokinase assay using the Architect c8000. Fifteen pairs of these tubes were kept in the refrigerator at 4°C and plasma/serum glucose concentrations were measured daily up to seven days after collection.  Results: Comparing plasma (NaF and serum (SST results of glucose values (n=50 showed an average difference of 0.00mmol/L (range -0.60 to +0.60mmol/L. Bland Altman analysis gave a non-significant constant bias of 0.10 ±0.195mmol/L (bias ±SD. Pearson correlation between plasma (NaF and serum (SST glucose concentrations revealed a significant correlation approaching unity with r2= 0.9991. No significant differences in glucose values were noted for both plasma and serum in 15 pairs of NaF and SST tubes when analyzed seven days following refrigeration. Hemolysis was observed in five (10% NaF tubes compared with two (4% SST.  Conclusion: There is no difference in glucose values collected from plasma NaF tubes or serum SST, and so SST can be used in hospital laboratory settings as there are practical advantages, including cost-effectiveness and reduction in blood volume drawn when utilizing these tubes for glucose and other tests from a single blood collection tube.

  16. Bottled Water and Fluoride

    Science.gov (United States)

    ... Fluoridation Journal Articles for Community Water Fluoridation Bottled Water Recommend on Facebook Tweet Share Compartir Consumers drink ... questions about bottled water and fluoride. Does bottled water contain fluoride? Bottled water products may contain fluoride, ...

  17. Unsustainability of water resources in the Upper Laja River Basin, Mexico: Social-hydrology interactions in a regional overexploited aquifer with increasing concentrations of fluoride, arsenic and sodium

    Science.gov (United States)

    Ortega, A.

    2013-05-01

    The Upper Laja River Basin, also known as the Independence Basin (IB), with an area of 7,000 km2 and a population near to 500,000 inhabitants is part of the regional Lerma-Chapala Basin in Central Mexico. Groundwater is the main source for drinking water supply, agriculture and industrial uses. Total groundwater extraction is in the order of 1,000 million of m3/a, through near to 3,000 wells in the basin, from which about 85% is for agriculture production, mainly for exportation. Historical hydrologic information in the basin showed the existence of numerous streams, rivers and lakes within the catchments in addition to thousands of springs in the discharge area. At present there is not permanent runoff in the main river and most of the springs and associated ecosystems have disappeared. Water table in the aquifer is between 100 and 200 m depth with decreasing rates between 2 m/a and 10 m/a, while 60 years ago water tables was near ground surface. Dissolved concentration of arsenic and fluoride in groundwater is increasing with time, causing severe health effects in rural villages and more recently in the main urban centers. Increasing concentration of sodium is affecting soil productivity and plant grow, where several hectares of land are been abandoned. There are several pieces of evidence that show the unsustainability of water resources in the IB creating complex social-hydrology interactions: Human actions are impairing the long-term renewability of freshwater stocks and flows. Basic water requirement are not been guaranteed to all inhabitants to maintain human health, neither to restore nor to maintain the remaining ecosystems. Water quality does not meet certain minimum standards in most of the basin. Water-planning and decision making are not democratic, the COTAS, a representation of water users is controlled by farmers with political power; therefore, limiting the participation of other parties and fostering direct participation of affected interests

  18. Adsorption of High Fluoride in Drinking Water by Aluminum Sulfate Impregnated Activated Alumina Granules%硫酸铝浸渍活性氧化铝球吸附饮水中的高浓度氟

    Institute of Scientific and Technical Information of China (English)

    吴代赦; 刘容; 杜俊逸; 李萍

    2011-01-01

    Aluminum sulfate impregnated activated alumina granules (AIAA) are the common adsorbent for high fluoride (F) drinking water, the adsorption properties of AIAA were influenced by sorts of factors. In batch adsorption experiments, the adsorption performance of AIAA in high fluoride drinking water was investigated by examining the effects of different factors, including AIAA amount to fluoride solution volume (m(AIAA): V) (2 -40 g · L-1) ,fluoride mass concentration (ρ(F)) (2 - 100 mg · L-1) ,pH (4 - 10) ,temperature ( 11 -33 ℃ ) and time on fluoride adsorption. Under the conditions of 11 -33 ℃ ,pH of 4 - 10,m(AIAA) : V at 20 g · L-1 ,AIAA could remove more than 90% F- for fluoride-containing water (10 mg · L-1) after 3 h,which satisfied sufficiently with the hygienic standard for F in drinking water. Langmuir and Freundlich models were adopted to fit the adsorption data. The results showed that the linear Langmuir model was the best fitting method at ρ(F) from 2 to 100 mg · L-1 ,pH from 5 to 10 and temperature from 11 to 33 ℃ ; and the non-linear Freundlich model was the best fitting method at ρ(F) from 2 to 1 000 mg· L-1 or at ρ(F) from 2 to 100 mg ·L -1 ,and pH at 4. With the increasing of ρ(F) in solution and temperature, the decreasing of solution pH, the adsorption capacity of AIAA was increased gradually.%硫酸铝浸渍活性氧化铝球(AIAA)是饮水除氟领域常用的吸附剂,它对氟的吸附性能受各种因素的影响.静态吸附通过改变AIAA质量与氟溶液体积比(m(AIAA):V)(2~40g·L-1)、氟的质量浓度(p(F))(2~100mg·L-1)、pH值(4~10)、温度(11~33℃)和时间等实验参数,研究这些因素对AIAA吸附除氟的影响.在11~33℃的温度范围内、pH值变化为4~10之间时,当m(AIAA):V为20 g·L-1,3 h内处理ρ(F)为10 mg·L-1水溶液其氟的去除率可达90%以上,足以保证其满足饮用水的含氟标准.利用Langmuir和Freundlich模型对吸附数据进行了拟合研

  19. Fabrication and icing property of superhydrophilic and superhydrophobic aluminum surfaces derived from anodizing aluminum foil in a sodium chloride aqueous solution

    Science.gov (United States)

    Song, Meirong; Liu, Yuru; Cui, Shumin; Liu, Long; Yang, Min

    2013-10-01

    An aluminum foil with a rough surface was first prepared by anodic treatment in a neutral aqueous solution with the help of pitting corrosion of chlorides. First, the hydrophobic Al surface (contact angle around 79°) became superhydrophilic (contact angle smaller than 5°) after the anodizing process. Secondly, the superhydrophilic Al surface became superhydrophobic (contact angle larger than 150°) after being modified by oleic acid. Finally, the icing property of superhydrophilic, untreated, and superhydrophobic Al foils were investigated in a refrigerated cabinet at -12 °C. The mean total times to freeze a water droplet (6 μL) on the three foils were 17 s, 158 s and 1604 s, respectively. Thus, the superhydrophilic surface accelerates the icing process, while the superhydrophobic surface delays the process. The main reason for this transition might mainly result from the difference of the contact area of the water droplet with Al substrate: the increase in contact area with Al substrate will accelerate the heat conduct process, as well as the icing process; the decrease in contact area with Al substrate will delay the heat conduct process, as well as the icing process. Compared to the untreated Al foil, the contact area of the water droplet with the Al substrate was higher on superhydrophilic surface and smaller on the superhydrophobic surface, which led to the difference of the heat transfer time as well as the icing time.

  20. Environmental fluoride

    Energy Technology Data Exchange (ETDEWEB)

    Marier, J.R.; Rose, D.

    1971-01-01

    Modern-day man is probably exposed to more environmental fluoride than was heretofore suspected, and consideration must be given to the total ingestion from various sources as well as the types of fluoride present in air, foods, beverages, and other commodities. An effort should also be made to study the symptomology of chronic fluorine intoxication, especially the early non-skeletal manifestations of arthritic-like symptoms that may be complicated by metabolic and/or nutritional inadequacies. Finally, it must be emphasized again that dental fluorosis (i.e. mottling) will only be seen in subjects who have been exposed to fluoride during the time when the enamel of the permanent teeth is being formed, and its absence cannot be assumed to indicate freedom from other fluoride-induced effects including effects of organofluorides and their metabolites. 168 references.

  1. Synthesis, quality control and dosimetry of the radiopharmaceutical 18F-sodium fluoride produced at the Center for Development of Nuclear Technology - CDTN

    Directory of Open Access Journals (Sweden)

    Marina Bicalho Silveira

    2010-09-01

    Full Text Available 18F-Sodium fluoride (Na18F is a radiopharmaceutical used for diagnosis in nuclear medicine by positron emission tomography (PET imaging. Bone scintigraphy is normally performed using 99mTc-MDP. However, 18F PET scans promise high quality imaging with increased resolution and improved sensitivity and specificity. In order to make available a tool for more specific studies of tumors and non-oncological diseases of bone tissue, the UPPR/CDTN team undertook the production and quality control of Na18F injectable solution with the physical-chemical, microbiological and biological characteristics recommended in the U.S. Pharmacopeia. Na18F radiochemical purity was 96.7 ± 1.3 %, with Rf= 0.026 ± 0.006. The product presented a pH of 5.3 ± 0.6, half life of 109.0 ± 0.8 minutes, endotoxin limit O Fluoreto de sódio 18F (Na18F é um radiofármaco empregado para diagnóstico através da Tomografia por Emissão de Pósitrons (PET. Cintilografias ósseas são normalmente obtidas utilizando-se 99mTc-MDP. Entretanto, o interesse pelo Na18F é crescente, principalmente devido à obtanção de imagens de elevada resolução. Com o objetivo de tornar disponível uma ferramenta mais específica para estudos de tumores e doenças não-oncológicas do tecido ósseo, o grupo da UPPR/CDTN implementou a produção e o controle de qualidade da solução injetável de Na18F com as características físico-química, microbiológica e biológica preconizadas pela farmacopéia. Sua pureza radioquímica foi de 96,7 ± 1,3 %, com Rf= 0,026 ± 0,006. O produto apresentou pH igual a 5,3 ± 0,6, tempo de meia-vida de 109,0 ± 0,8 minutos, limite de endotoxinas < 5,0 EU.mL-1 e ausência de microrganismos. O perfil de biodistribuição em camundongos foi semelhante ao disponível na literatura, com depuração igual a 0,19 mL.min-1 e volume de distribuição igual a 18,76 mL. A concentração máxima (5,0 ± 0,5 % DI.g-1 foi observada no osso 20 minutos após a injeção. O Na18

  2. Other Fluoride Products

    Science.gov (United States)

    ... Water Fluoridation Journal Articles for Community Water Fluoridation Other Fluoride Products Recommend on Facebook Tweet Share Compartir ... Use the information listed below to compare the other fluoride products that may lower the risk for ...

  3. Batch and Column Experiments on Fluoride Removal from Waters Using Modified Zeolite

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    High fluoride groundwater occurs widely in China, presenting a quite serious environmental problem. Zeolite from Xinyang, China was tested as the fluoride-removing adsorbent. Batch and column experiments on fluoride removal using modified zeolites treated with hydrochloric acid,sodium hydroxide, sodium chloride and ferric chloride, respectively show that 0. 1 mol/L HCImodified zeolite can be used as an adsorbent for fluoride, with an adsorption capacity of 173. 16mg/kg.

  4. Exraction and separation of CERIUM(IV)/FLUORINE in fluoride-bearing cerium sulfate solution with fluoride coordination agent

    OpenAIRE

    Li, Y; J. G. He; X. X. Xue; Ru, H. Q.; X. W. Huang; Yang, H.

    2014-01-01

    In this paper the extraction and separation of cerium/fluorine in fluoride-bearing cerium sulfate solution with fluoride coordination agent has been studied. The UV-vis spectra suggest that Zr6+ and Al3+ can scrub the F- from [CeF2] 2+ complex. The separation and conductivity studies show that aluminum salt is the most suitable fluoride coordination agent, and an ion-exchange reaction is involved between Ce4+/ [CeF2] 2+ and hydrogen ion.

  5. The effect of electron irradiation on the structure and iron speciation in sodium aluminum (iron) phosphate glasses

    Science.gov (United States)

    Stefanovsky, S. V.; Presniakov, I. A.; Sobolev, A. V.; Glazkova, I. S.; Kadyko, M. I.; Stefanovsky, O. I.

    2016-08-01

    The effect of 8 MeV electron irradiation on the structure of glasses in the series 40 Na2O, (20-x) Al2O3, x Fe2O3, 40 P2O5 (mol.%) and on the iron speciation in these samples was studied by FTIR and Mössbauer spectroscopic techniques. Irradiation up to a dose of 1.0 MGy has no appreciable effects on the character of the bonds within anionic motif of the glass network. Electron irradiation increases the fraction of aluminum in octahedral coordination. Iron in both unirradiated and irradiated glasses is present mainly as Fe(III) (60-75% of the total amount) in the glasses and partly as Fe(II) and the ratio of two forms remains constant up to a dose of 1.0 MGy.

  6. Evaluation of the substantivity of chlorhexidine in association with sodium fluoride in vitro Avaliação da substantividade da clorexidina na associação com fluoreto de sódio in vitro

    Directory of Open Access Journals (Sweden)

    Carolina Saliba de Freitas

    2003-03-01

    Full Text Available The efficacy of the fluoride-chlorhexidine association in the prevention of gingivitis and caries has been advocated for a number of years5,7,14. The objective of the association of these therapeutic agents is a synergistic action. The aim of the present study was to determine the substantivity of chlorhexidine associated or not to sodium fluoride at different intervals of time, in vitro. Bovine enamel surfaces were treated with 0.12% chlorhexidine gluconate (Periogard® - Colgate® or 0.05% sodium fluoride with 0.12% chlorhexidine (Duplak® - Dentsply® solutions for one minute. Fragments were placed in distilled water and samples were collected at intervals of 5, 30 and 360 minutes and analyzed by spectrophotometry in the visible ultraviolet region. Substantivity was evaluated by the measurement of chlorhexidine desorption from the treated slabs. The mean values obtained were statistically analyzed by Student's t-test. The results showed that the concentration of chlorhexidine decreased when it was used in association with sodium fluoride. The difference between the groups was statistically significant (p A efetividade da associação fluoreto-clorexidina na prevenção da gengivite e da cárie vem sendo defendida há alguns anos5,7,14. O propósito dessa associação é obter um desempenho sinérgico. O objetivo do presente estudo foi avaliar a substantividade da clorexidina em associação ou não ao fluoreto de sódio em diferentes intervalos de tempo, in vitro. Foram tratadas superfícies de esmalte bovino com soluções de digluconato de clorexidina 0,12% (Periogard® - Colgate® ou fluoreto de sódio 0,05% com clorexidina 0,12% (Duplak® - Dentsply®, durante um minuto. A substantividade foi medida pela dessorção da clorexidina a partir dos fragmentos previamente imersos nas soluções teste e colocados em água destilada. Alíquotas foram removidas em intervalos de 5 minutos, 30 minutos e 6 horas e analisadas através de

  7. Analysis of 1-Minute Potentially Available Fluoride from Dentifrice

    Science.gov (United States)

    Carey, Clifton M; Holahan, Erin C; Schmuck, Burton D

    2014-01-01

    Previous reports found that some fluoride-containing dentifrices do not release effective concentrations of fluoride during brushing. Failure to release fluoride can be due to dentifrice matrix components that interfere with the solubilization of the fluoride salts during brushing. A new generation of dentifrices has the capability to precipitate beneficial fluoride salts during tooth brushing. Therefore, a method that assesses the potentially available fluoride during the 1-minute brushing is needed. A new filter-paper absorption method to assess the 1-min bioavailable fluoride concentration was developed to meet this need. This method utilizes coiled filter paper that rapidly absorbs the aqueous phase of the dentifrice slurry followed by centrifugation to recover that fluid for fluoride measurement via fluoride ion-selective electrode. The analytical method was used to successfully determine the total fluoride and 1-min bioavailable fluoride in eight dentifrice products containing sodium fluoride (NaF), disodium monofluorophosphate (Na2FPO3, MFP), stannous fluoride (SnF2), or NaF with amorphous calcium phosphate (NaF + ACP). The results showed that some of the dentifrices tested had significantly lower potentially available fluoride than the total fluoride. For a MFP-containing sample, aged seven years past its expiry date, there was significant reduction in the bioavailable fluoride compared to MFP products that were not aged. Other than the aged MFP and the SnF2-containing samples the bioavailable fluoride for all products tested had at least 80 % of the label fluoride concentration. The filter paper absorption method yielded reproducible results for the products tested with MFP samples showing the largest variations. PMID:25821392

  8. Absorption of silicon and aluminum by hens fed sodium zeolite A with various levels of dietary cholecalciferol.

    Science.gov (United States)

    Rabon, H W; Roland, D A; Bryant, M M; Smith, R C; Barnes, D G; Laurent, S M

    1995-02-01

    Two experiments were conducted to determine whether 1) serum Si and Al is increased in hens intubated with sodium zeolite A (SZA); and 2) dietary cholecalciferol (vitamin D3) influences the absorption of Si or Al by hens fed SZA. In Experiment 1, hens were intubated at oviposition with 0, 1, or 2 g of SZA. Blood samples were collected from the brachial vein at oviposition, and 4, 8, 12, 16, and 20 h postoviposition. Serum samples were analyzed for Si and Al. Peak serum Si and Al were observed at 4 and 8 h postoviposition, respectively. In Experiment 2, hens consumed commercial layer diets ad libitum containing five levels of dietary cholecalciferol (100 to 500 IU/kg) with or without .75% SZA for 6 wk. Blood samples were collected at the end of the 6-wk period by cardiac puncture at oviposition. When dietary cholecalciferol was increased from 100 to 200 IU/kg of diet there was an increase (P < .05) in serum Si but not Al. Levels of cholecalciferol above 200 IU/kg did not produce an additional increase in serum Si. The results showed increased (P < .01) serum concentrations of Si and Al for hens intubated with or fed SZA. It was concluded that Si and Al from SZA are absorbed by commercial Leghorn hens, and a possible involvement of Si or Al should be considered in the mechanism of action of SZA associated with improved eggshell quality and bone development.

  9. Technical Status Report on the Effect of Phosphate and Aluminum on the Development of Amorphous Phase Separation in Sodium

    Energy Technology Data Exchange (ETDEWEB)

    Cozzi, A.D.

    1998-11-03

    The objective of the Tank Focus Area ''Optimize Waste Loading'' task is to enhance the definition of the acceptable processing window for high-level waste vitrification plants. One possible manner in which the acceptable processing window may be enhanced is by reducing the uncertainty of various compositional/property models through a specifically defined experimental plan. A reduction in model uncertainty can reduce limitations on current acceptance constraints and may allow for a larger processing or operational window. Enhanced composition/property model predictions coupled with an increased waste loading may decrease the processing time and waste glass disposal costs (i.e., overall lifecycle costs). One of the compositional/property models currently being evaluated by the Tanks Focus Area is related to the development of amorphous phase separation in multi-component borosilicate glasses.Described in this report is the current status for evaluating the effect of phosphorus and alumina on both simple sodium borosilicate and high-level waste glasses on the formation of amorphous phase separation. The goal of this subtask is to increase the understanding of the formation of phase separation by adding significant amounts (3-5 wt. percent) of phosphorus and alumina to well-characterized glasses. Additional scope includes evaluating the effects of thermal history on the formation of amorphous phase separation and durability of select glasses.The development of data, understanding, and quantitative description for composition and kinetic effects on the development of amorphous phase separation will continue in FY99. This effort will provide insight into the compositional and thermal effects on phase stability and will lead to a better understanding of the methods used to predict the development of amorphous phase separation in HLW glasses.

  10. Effects of fluoridated milk on root dentin remineralization.

    Directory of Open Access Journals (Sweden)

    Wolfgang H Arnold

    Full Text Available The prevalence of root caries is increasing with greater life expectancy and number of retained teeth. Therefore, new preventive strategies should be developed to reduce the prevalence of root caries. The aim of this study was to investigate the effects of fluoridated milk on the remineralization of root dentin and to compare these effects to those of sodium fluoride (NaF application without milk.Thirty extracted human molars were divided into 6 groups, and the root cementum was removed from each tooth. The dentin surface was demineralized and then incubated with one of the following six solutions: Sodium chloride NaCl, artificial saliva, milk, milk+2.5 ppm fluoride, milk+10 ppm fluoride and artificial saliva+10 ppm fluoride. Serial sections were cut through the lesions and investigated with polarized light microscopy and quantitative morphometry, scanning electron microscopy (SEM and energy-dispersive X-ray spectroscopy (EDS. The data were statistically evaluated using a one-way ANOVA for multiple comparisons.The depth of the lesion decreased with increasing fluoride concentration and was the smallest after incubation with artificial saliva+10 ppm fluoride. SEM analysis revealed a clearly demarcated superficial remineralized zone after incubation with milk+2.5 ppm fluoride, milk+10 ppm fluoride and artificial saliva+10 ppm fluoride. Ca content in this zone increased with increasing fluoride content and was highest after artificial saliva+10 ppm fluoride incubation. In the artificial saliva+10 ppm fluoride group, an additional crystalline layer was present on top of the lesion that contained elevated levels of F and Ca.Incubation of root dentin with fluoridated milk showed a clear effect on root dentin remineralization, and incubation with NaF dissolved in artificial saliva demonstrated a stronger effect.

  11. Professionally applied fluoride gel in low-caries 10.5-year-olds.

    NARCIS (Netherlands)

    Truin, G.J.; Hof, M.A. van 't

    2005-01-01

    The question has been raised whether low-caries children regularly using fluoride toothpaste will benefit from the professional application of additional fluoride gel. To investigate the caries-reducing effect of semi-annually-applied neutral 1% sodium fluoride gel, we carried out a double-blind ran

  12. Evaluation of dentinal tubule occlusion and depth of penetration of nano-hydroxyapatite derived from chicken eggshell powder with and without addition of sodium fluoride: An in vitro study

    Directory of Open Access Journals (Sweden)

    Divya Kunam

    2016-01-01

    Full Text Available Aim: This in vitro study evaluated the degree of dentinal tubule occlusion and depth of penetration of nano-hydroxyapatite (nHAp derived from chicken eggshell powder with and without the addition of 2% sodium fluoride (NaF using scanning electron microscope (SEM and confocal laser scanning microscope (CLSM. Materials and Methods: nHAp was synthesized and characterized using X-ray diffraction and SEM-energy dispersive spectroscopy. Dentin discs were obtained from extracted teeth, pretreated with 17% ethylenediaminetetraacetic acid for 5 min and were divided into four groups based on the experimental agents as follows: Group 1: Untreated (control, Group 2: 2% NaF, Group 3: nHAp, Group 4: Combination of nHAp and 2% NaF. The treatment protocol was carried out for 7 days, after which the specimens were viewed under SEM and CLSM. Statistical Analysis Used: One-way ANOVA and Tukey′s post hoc multiple comparison tests (P < 0.05. Results: All the experimental agents occluded the dentinal tubules, but to varying degrees and depths. Specimens treated with the combination of nHAp and 2% NaF showed complete dentinal tubular occlusion and significantly greater depth of penetration than those treated with nHAp and 2% NaF alone. Conclusion: The combination of nHAp and 2% NaF was the most effective in occluding dentinal tubules.

  13. Comparison of in vitro fluoride uptake from whitening toothpastes and a conventional toothpaste in demineralised enamel.

    Science.gov (United States)

    Altenburger, Markus J; Bernhart, Jasmin; Schicha, Thurid D; Wrbas, Karl-Thomas; Hellwig, Elmar

    2010-01-01

    Studies on the compatibility of abrasives and fluoride compounds deal exclusively with fluoride uptake and remineralization after storing the enamel specimens in a toothpaste-saliva mixture. The influence of brushing on the fluoride uptake when highly abrasive toothpastes are used has hardly been investigated so far. The aim of the present study was to investigate fluoride uptake in initially demineralised dental enamel after storage in, or brushing with, whitening toothpaste slurries, compared to a conventional toothpaste. For this purpose two widely available whitening toothpastes with ionically bound fluoride (sodium fluoride NaF), two with covalently-bound fluoride toothpastes (sodium monofluorophosphate, NaMFP) and a conventional amine fluoride toothpaste (AmF) were compared. The fluoride uptake after use of the AmF toothpaste was shown to be statistically significantly higher than that after application of the NaF toothpastes, which in turn was statistically significantly higher than the uptake resulting from NaMFP application. The fluoride uptake was slightly higher when the enamel samples were brushed with NaF toothpaste, rather than just stored in the respective toothpaste slurry. Brushing with highly abrasive toothpastes did not negatively influence fluoride uptake in demineralised dental enamel. The ionic form of the fluoride in toothpastes appears to be critical for increased fluoride uptake. The acidic components of the AmF toothpaste improved fluoride uptake compared to alkaline NaF toothpastes.

  14. 铝对氟中毒小鼠斑状脱毛的保护作用%Protective effect of aluminum on hair loss induced by fluoride in fluorosis mice

    Institute of Scientific and Technical Information of China (English)

    裴俊瑞; 李丙云; 高彦辉; 周令望; 孙殿军

    2013-01-01

    目的 探讨铝对氟中毒小鼠斑状脱毛的保护作用,氟对小鼠皮肤的损伤及铝对氟毒性的拮抗作用.方法 60只雄性C57/BL小鼠按体质量随机分为对照组、氟组(氟离子100 mg/L)、铝组(铝离子270mg/L)和氟+铝组(氟离子100 mg/L+铝离子270 mg/L),每组15只,分别在饲养1、3个月时处死取骨组织.离子选择电极法检测骨氟含量;电感耦合等离子体发射光谱法测定骨铝水平;观察小鼠氟斑牙和脱毛发生情况.结果 饲养1个月时,各组小鼠均无氟斑牙和脱毛现象发生;氟组、氟+铝组、对照组、铝组骨氟依次降低,分别为(2401.649±86.835)、(1210.332±19.531)、(538.001±33.337)、(427.006±11.878)mg/kg,任意两组组间比较,差异均有统计学意义(P均< 0.05).饲养3个月时,氟组10只小鼠均发生氟斑牙和斑状脱毛,脱毛区域位于颈部和背部,其他体表部位未见脱毛现象,而对照组、铝组和氟+铝组小鼠均无脱毛现象,并且对照组和铝组无氟斑牙发生,氟+铝组仅有2例轻度氟斑牙发生;氟组、氟+铝组、对照组、铝组骨氟从高到低依次为(4098.645±58.842)、(1888.165±12.187)、(876.258±14.462)、(662.385±8.966)mg/kg,任意两组组间比较,差异均有统计学意义(P均< 0.05).结论 氟中毒小鼠有脱毛现象发生,小鼠脱毛与氟暴露程度密切相关;铝通过减少氟在体内的蓄积而预防染氟小鼠脱毛的发生.%Objective To investigate the effect of aluminum on hair loss induc ed by fluoride in fluorosis mice.Methods Sixty male C57BL mice were divided into four groups according to body mass:control group,fluoride (F) group (F-100 mg/L),aluminum(Al) group(Al3+ 270 mg/L) and F + Al group(F-100 mg/L + Al3+270 mg/L).Mice were killed 1 month and 3 months after the experiment,respectively.Bone F content was detected by ion-selective electrode method.The level of bone Al was measured through inductively coupled plasma emission spectrum

  15. Aluminum nitrate (Al(NO3)3) as defluoridating agent in drinking water soil pots (vessels of earthenware).

    Science.gov (United States)

    Yadav, R N; Yadav, Rajdeep

    2011-10-01

    Presence of fluoride in drinking water above (and sometimes even below) permissible limit (1.5 ppm according to WHO) leads to fluorosis. Aluminum salts are commonly used as coagulants in water treatments. Aluminum fluoride is less toxic than other fluorides. The concentration of fluoride was determined by the fluoride ion selective electrode method. In this study, Al (NO3)3 was incorporated in different amounts in soil and prepared soil pots by the mixture. It is observed that these soil pots remarkably decrease the concentration of fluoride in drinking water. Langmuir and Freundlich isotherm studies were also carried out.

  16. Advances in aluminum pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    Sudour, Michel; Maintier, Philippe [PPG Industries France, 3 Z.A.E. Les Dix Muids, B.P. 89, F-59583 Marly (France); Simpson, Mark [PPG Industries Inc., 1200 Piedmont Troy, Michigan 48083 (United States); Quaglia, Paolo [PPG Industries Italia, Via Garavelli 21, I-15028 Quattordio (Italy)

    2004-07-01

    As automotive manufacturers continue to look for ways to reduce vehicle weight, aluminum is finding more utility as a body panel component. The substitution of cold-rolled steel and zinc-coated substrates with aluminum has led to new challenges in vehicle pretreatment. As a result, changes to traditional pretreatment chemistries and operating practices are necessary in order to produce an acceptable coating on aluminum body panels. These changes result in increased sludging and other undesirable characteristics. In addition to the chemistry changes, there are also process-related problems to consider. Many existing automotive pretreatment lines simply were not designed to handle aluminum and its increased demands on filtration and circulation equipment. To retrofit such a system is capital intensive and in addition to requiring a significant amount of downtime, may not be totally effective. Thus, the complexities of pre-treating aluminum body panels have actually had a negative effect on efforts to introduce more aluminum into new vehicle design programs. Recent research into ways of reducing the negative effects has led to a new understanding of the nature of zinc phosphate bath -aluminum interactions. Many of the issues associated with the pretreatment of aluminum have been identified and can be mitigated with only minor changes to the zinc phosphate bath chemistry. The use of low levels of soluble Fe ions, together with free fluoride, has been shown to dramatically improve the efficiency of a zinc phosphate system processing aluminum. Appearance of zinc phosphate coatings, coating weights and sludge are all benefited by this chemistry change. (authors)

  17. Effect of Sodium Molybdate Inhibitor on Corrosion Resistance of 5083 Aluminum Alloy Used for Drone%钼酸钠对靶用5083铝合金耐蚀性能影响的研究

    Institute of Scientific and Technical Information of China (English)

    杨志成; 周宽; 田志强

    2016-01-01

    目的:提高靶用5083铝合金材料的耐蚀性。方法分别运用阳极极化、交流阻抗及EDS等试验技术研究钼酸钠对5083铝合金在3%氯化钠溶液中的耐蚀性能影响。结果钼酸钠加入3%氯化钠溶液以后,该铝合金的腐蚀电位下降,点蚀电位与腐蚀电位分离,维钝电流减小,阻抗值增大,抗点蚀能力提高。结论钼酸钠对5083铝合金产生缓蚀作用。%Objective To improve the corrosion resistance of 5083 aluminum alloy used for drone.Methods The polariza-tion, electrochemical impedance spectrum and energy dispersive spectrometer were employed to study the effect of sodium mo-lybdate inhibitor on the corrosion resistance of 5083 aluminum alloy in 3% NaCl solution.Results After addition of sodium molybdate in the 3% NaCl solution, the corrosion potential was decreased and separated from the pitting potential, the passi-vated current was reduced, the impedance was increased, and the capability of inhibiting pitting was promoted.Conclusion So-dium molybdate had corrosion inhibition effect on 5083 aluminum alloy.

  18. A method for producing controlled fluoride release from an orthodontic bracket.

    Science.gov (United States)

    Li, Song; Hobson, Ross S; Bai, Yuxing; Yan, Zhuoqun; Carrick, Thomas E; McCabe, John F

    2007-12-01

    The aim of this study was to manufacture and test, in vitro, a novel modification to provide fluoride-releasing orthodontic brackets. Thirty-two orthodontic brackets were drilled to produce a recess (approximately 1.3 mm in diameter and 0.7 mm in depth) at the centre of the bracket base. Four materials, with and without the addition of sodium fluoride, a glass ionomer cement (Ketac Cem micro), a resin-modified glass ionomer cement (RMGIC; GC Fuji Ortho LC), a zinc phosphate (Zinc Cement Improved), and a resin (Transbond XT) were used to fill the recess in the bracket base. Fluoride release was measured daily during the first week and then weekly for 10 weeks. An ion chromatograph with suppressed conductivity was used for free fluoride ion determination. Statistical analysis to determine the amount of flouride release was undertaken using analysis of variance and Tukey's test. During the first 2 weeks, the resin group, with the addition of 38 per cent sodium fluoride added, released significantly more free fluoride (P < 0.05), but after 2 weeks the fluoride release markedly decreased. After 5 weeks, the RMGIC group, with 15 per cent added sodium fluoride, had significantly higher (P < 0.05) daily fluoride release than the other groups. The findings demonstrated that an appropriate fluoridated material can be used as a fluoride-releasing reservoir in a modified orthodontic bracket to enable it to release fluoride over the period of fixed appliance treatment.

  19. Comparisons between glucose analogue 2-deoxy-2-(18F)fluoro-D-glucose and 18F-sodium fluoride positron emission tomography/computed tomography in breast cancer patients with bone lesions

    Institute of Scientific and Technical Information of China (English)

    Selene Capitanio; Francesca Bongioanni; Arnoldo Piccardo; Claudio Campus; Roberta Gonella; Lucia Tixi; Mehrdad Naseri; Michele Pennone; Vania Altrinetti; Ambra Buschiazzo; Irene Bossert; Francesco Fiz; Andrea Bruno; Andrea DeCensi; Gianmario Sambuceti; Silvia Morbelli

    2016-01-01

    AIM: To compare 2-deoxy-2-(18F)fluoro-D-glucose(18FFDG) and 18F-sodium(18F-NaF) positron emission tomography/computed tomography(PET/CT) accuracy in breast cancer patients with clinically/radiologically suspected or known bone metastases.METHODS: A total of 45 consecutive patients with breast cancer and the presence or clinical/biochemical or radiological suspicion of bone metastatic disease underwent 18F-FDG and 18F-fluoride PET/CT. Imaging results were compared with histopathology when available, or clinical and radiological follow-up of at least 1 year. For each technique we calculated: Sensitivity(Se), specificity(Sp), overall accuracy, positive and negative predictive values, error rate, and Youden’s index. Mc Nemar’s χ2 test was used to test the difference in sensitivity and specificity between the two diagnostic methods. All analyses were computed on a patient basis, and then on a lesion basis, with consideration ofthe density of independent lesions on the coregistered CT(sclerotic, lytic, mixed, no-lesions) and the divergent site of disease(skull, spine, ribs, extremities, pelvis). The impact of adding 18F-Na F PET/CT to the work-up of patients was also measured in terms of change in their management due to 18F-Na F PET/CT findings. RESULTS: The two imaging methods of 18F-FDG and 18F-fluoride PET/CT were significantly different at the patient-based analysis: Accuracy was 86.7% and 84.4%, respectively(Mc Nemar’s χ2 = 6.23, df = 1, P = 0.01). Overall, 244 bone lesions were detected in our analysis. The overall accuracy of the two methods was significantly different at lesion-based analysis(Mc Nemar’s χ2 = 93.4, df = 1, P < 0.0001). In the lesion density-based and site-based analysis, 18F-FDG PET/CT provided more accurate results in the detection of CT-negative metastasis(P < 0.002) and vertebral localizations(P < 0.002); 18F-Na F PET/CT was more accurate in detecting sclerotic(P < 0.005) and rib lesions

  20. Qualidade seminal e histomorfometria dos órgãos reprodutivos de ovinos tratados com fluoreto de sódio Seminal quality and reproductive histomorphometry of ram lambs treated with sodium fluoride

    Directory of Open Access Journals (Sweden)

    Andreane Filappi

    2008-12-01

    Full Text Available O presente estudo objetivou avaliar as características espermáticas, os indicadores do metabolismo oxidativo do sêmen, o diâmetro dos túbulos seminíferos e a altura do epitélio testicular, do epididimário e do canal deferente de ovinos tratados com fluoreto de sódio. Foram utilizados 12 ovinos, com idade aproximada de cinco meses. Os animais foram divididos em grupo controle, o qual recebeu diariamente sal iodado (5g de NaCl animal-1 + 0,2mg I kg-1 matéria seca, e tratado, que recebeu sal iodado adicionado de fluoreto de sódio (4,7mg F kg-1 de peso corporal. Aos 150 dias de tratamento, foram realizadas coletas de sêmen e, em seguida, os animais foram eutanasiados. Na comparação entre o grupo controle e o tratado, não foram observadas diferenças no percentual de motilidade, vivos : mortos e morfologia espermática, na concentração da glutationa reduzida seminal, no teor de zinco seminal, no peso testicular, na morfometria e na histologia do testículo, na cauda do epidídimo e no canal deferente. A concentração de substâncias reativas ao ácido tiobarbitúrico (TBARs e o teor de cobre no sêmen foram menores (PThe objective of the present study was to evaluate different reproductive parameters of ram lambs treated with sodium fluoride. Spermogram, indicators of seminal oxidative profile, seminiferous tubules diameter and cell height of the testicular epithelium, epididimus and vas deferens were analyzed. Twelve 5-month-old ram lambs were used. They were allocated into one of two experimental groups: The control, which received daily iodized salt (5g NaCl animal-1 + 0.2mg I kg-1 DM; and the treated, which received (5g NaCl animal-1 + 0.2mg I kg-1 DM + 4.7mg F kg-1 BW. After 150 days of treatment, animals went through a complete andrological exam, and were euthanized on the next day. No differences were observed in sperm motility, dead: alive ratio and morphology between the control and treated group. Also, seminal

  1. 2%氟化钠防龋功效在托幼机构3~4岁儿童组三年应用观察及分析%Observes and analyzes in the kindergarten 3-4 year old child group to apply 2% sodium fluoride prevention dental caries in three years the effect

    Institute of Scientific and Technical Information of China (English)

    钱哲

    2014-01-01

    目的:寻找简便有效的儿童防龋措施,以降低乳牙龋齿发病率。方法:选取托幼机构3~4岁儿童进行3年氟化物应用并观察疗效。结果:2%氟化钠涂布可以抑制乳牙龋齿的进展。结论:氟化钠涂布可有效防龋,但同时需要家庭和幼儿园共同配合,督促儿童养成良好的口腔卫生习惯,以期达到更好的防龋效果。%Goal:Seeks for the collective child simple and effective guards against the decayed tooth measure, reduces the milk teeth dental caries disease incidence rate. Method: The selection preschool 3-4 year old child carries on 3 years fluoride to apply and to observe the curative effect.Finally: Spreads 2% sodium fluoride to be possible to suppress the milk teeth dental caries the progress. Conclusion: Spreads the sodium fluoride to be possible to guard against the decayed tooth effectively, but simultaneously needs the family and the kindergarten coordinates, to supervise the child together to form the good oral hygiene habit, by the time achieved better guards against the decayed tooth effect.

  2. Fluoride varnish or fluoride mouth rinse?

    DEFF Research Database (Denmark)

    Keller, M K; Klausen, B J; Twetman, S

    2016-01-01

    OBJECTIVE: In many Danish communities, school-based fluoride programs are offered to children with high caries risk in adjunct to tooth brushing. The purpose of this field trial was to compare the caries-preventive effectiveness of two different fluoride programs in 6-12 year olds. BASIC RESEARCH...... different schools were enrolled after informed consent and their class unit was randomly allocated to one of two fluoride programs. INTERVENTIONS: One group received a semi-annual fluoride varnish applications (FV) and the other group continued with an existing program with fluoride mouth rinses once per...... in caries development over two years among children participating in a school-based fluoride varnish or mouth rinse program....

  3. Amelioration of Fluoride Toxicity with the Use of Indigenous Inputs

    Directory of Open Access Journals (Sweden)

    Maitra A.

    2013-08-01

    Full Text Available An assessment was undertaken to study the efficacy of bacterial consortia isolated from different sources viz. rhizosphere of rice plant, oil spill sites of a petrol pump and from the sludge of a pharmaceutical waste water drain against the impact of fluoride. The experiments were conducted with two crops. In this mung bean experiment Vigna radiata was selected as a test crop. The seeds were sown in the field with bacterial consortia, compost and reduced dose (25% less nitrogen than recommended dose of chemical fertilizer. After 30days of seed sowing (DAS, plants were collected from the field and dipped into the sodium fluoride solution with different concentrations for 48 hours. Thereafter, the impact of fluoride on chlorophyll, sugar, proline and relative water content (% were evaluated. Scanning electron microscopy (SEM of the stem section was performed. SEM studies revealed that anatomical structure deformed with 1.5 mg/l sodium fluoride solution. It was observed that such treatment combination during the sowing of crops leads to combat the impact of lower doses of sodium fluoride (0.2 mg/l. Another experiment was also conducted within plastic pots with and without bacterial consortia isolated from rhizosphere of rice plant and oil spilled soil of petrol pump with the same field soil. Each pot was filled with 5 kg of soil + 2lt of water (on the basis of soil saturation. Oryza sativa seedlings were transplanted with different strength of sodium fluoride solution (25 mgNaF/kg, 50 mgNaF/kg, 100 mgNaF/kg and 500mgNaF/kg within the above pots. In second experiment, rice plants dried in all pots after 500 mgNaF/kg concentration of sodium fluoride. In this pot experiment bacterial strain are capable of reducing fluoride content in soil as noted by measuring fluoride in the pot soil after the experiment.

  4. Effects of oral doses of fluoride on nestling European starlings

    Science.gov (United States)

    Fleming, W.J.; Grue, C.E.; Schuler, C.A.; Bunck, C.M.

    1987-01-01

    Nestling European starlings (Sturnus vulgaris), raised and fed by free-living adults, were given daily oral doses of either distilled water, 193 mg sodium as Na2CO3 per kg of body weight (sodium control group), or 6, 10, 13, 17,23, 30, 40, 80, 160 mg of the fluoride ion as NaF in distilled water per kg of body weight (mg/kg). Dosing began when nestlings were 24-48 hr old and continued for 16 days. The 24-hr LD50 of fluoride for day-old starlings was 50 mg/kg. The 16-day LD50 was 17 mg/kg. The sodium control group did not differ from the water control group with respect to any of the measured variables. Growth rates were significantly reduced in the 13 and 17 mg of fluoride/kg groups; weights of birds given higher dose levels were omitted from growth comparisons because of high, fluoride-induced mortality. Although pre-fledging weights for the 10, 13, and 17 mg of fluoride/kg groups averaged 3.6 to 8.6% less than controls at 17 days, this difference was not significant. Feather and bone growth of the fluoride and control groups were not different, except for keel length measured at 17 days of age which averaged less in the fluoride groups. Liver and spleen weights were not affected by fluoride treatments. No histological damage related to fluoride treatments was found in liver, spleen, or kidney. The logarithm of bone fluoride and magnesium concentration increased with the logarithm of increasing fluoride treatment levels and were significantly correlated with each other. Fluoride treatments had no effect on percent calcium or phosphorus in bone or plasma alkaline phosphatase activity. Oral doses of fluoride appear to be more toxic than equivalent dietary levels. Most birds probably acquire fluoride through their diet. Therefore, the results of the study may overestimate the potential effects of fluorides on songbirds living in fluoride-contaminated environments.

  5. Fluoride in diet

    Science.gov (United States)

    Diet - fluoride ... bones and teeth. Too much fluoride in the diet is very rare. Rarely, infants who get too ... of essential vitamins is to eat a balanced diet that contains a variety of foods from the ...

  6. Exraction and separation of CERIUM(IV/FLUORINE in fluoride-bearing cerium sulfate solution with fluoride coordination agent

    Directory of Open Access Journals (Sweden)

    Y. Li

    2014-07-01

    Full Text Available In this paper the extraction and separation of cerium/fluorine in fluoride-bearing cerium sulfate solution with fluoride coordination agent has been studied. The UV-vis spectra suggest that Zr6+ and Al3+ can scrub the F- from [CeF2] 2+ complex. The separation and conductivity studies show that aluminum salt is the most suitable fluoride coordination agent, and an ion-exchange reaction is involved between Ce4+/ [CeF2] 2+ and hydrogen ion.

  7. Sodium fluoride subchronic poison impact female mice estrogen receptor expression%氟化钠亚慢性染毒对雌性小鼠氧化损伤的研究

    Institute of Scientific and Technical Information of China (English)

    唐勇; 陈立宝; 王春; 王彩生; 徐耀初; 王仪

    2011-01-01

    Objective To study the subchronic toxicity of sodium fluoride on the estrogen receptor expression level of female mice. Method 40 ICR mice (female, weight 18 to 20 g)were randomly divided into 4 groups, 10 in each group, and exposed to sodium fluoride solution (0 mg/L ,1 mg/L 5 mg/L, 25 mg/L) from drinking water for 3 months. The fluorine concentrations in bone tissues were detected by fluorine ion selective electrode. The expression levels of Era, Erf}, IL - 6 mRNA were determined by RT - PCR method. Results Weight differences between groups were not statistically significant ( P > 0.05) . The organ coefficient of liver in control group was the highest, followed by low - dose group, medium - dose group and high - dose group (46.56 ±2.46), (47.03 ±6.25), (45.84 ±5.90), (42.19 ±3. 89). Compared with control group (4.98 ±0.25), the organ coefficients of bone in medium - dose and high - dose group (5.46±0.26), (5.46 ± 0.33) were significantly increased ( P < 0.05). The fluorine concentrations were gradually increased, from control group to high - dose group (711.37 ± 263.83), (998.75 ± 254. 87), (1195. 21 ± 159. 73), (1957.00 ± 273. 19) μg /g, and the differences between medium/high - dose group and control group were statistically significant ( P <0.05). RT - RCR results showed that estrogen receptor expression levels in ovarian tissues decrease with increased dose, and the difference between high - dose group and control group about the expression levels of Era was statistically significant ( P <0.05). Conclusions Fluoride can decrease the expression of estrogen receptor in ovarian tissue, and maybe affect the animal reproductive development.%目的 研究氟化钠亚慢性染毒对雌性小鼠所产生的氧化损伤.方法 取雌性小鼠40只,随机分成4组,每组10只.即对照组,氟低剂量组(1 mg/L),氟中剂量组(5 mg/L)、氟高剂量组(25 mg/L).经饮用水染毒3个月.计算脏器系数、测量骨组织氟浓度,用试剂盒测定血

  8. Removal of uranium and fluorine from wastewater by double-functional microsphere adsorbent of SA/CMC loaded with calcium and aluminum

    Science.gov (United States)

    Wu, Liping; Lin, Xiaoyan; Zhou, Xingbao; Luo, Xuegang

    2016-10-01

    A novel dual functional microsphere adsorbent of alginate/carboxymethyl cellulose sodium composite loaded with calcium and aluminum (SA/CMC-Ca-Al) is prepared by an injection device to remove fluoride and uranium, respectively, from fluoro-uranium mixed aqueous solution. Batch experiments are performed at different conditions: pH, temperature, initial concentration and contact time. The results show that the maximum adsorption amount for fluoride is 35.98 mg/g at pH 2.0, 298.15 K concentration 100 mg/L, while that for uranium is 101.76 mg/g at pH 4.0, 298.15 K concentration 100 mg/L. Both of the adsorption process could be well described by Langmuir model. The adsorption kinetic data is fitted well with pseudo-first-order model for uranium and pseudo-second-order model for fluoride. Thermodynamic parameters are also evaluated, indicating that the adsorption of uranium on SA/CMC-Ca-Al is a spontaneous and exothermic process, while the removal of fluoride is non-spontaneous and endothermic process. The mechanism of modification and adsorption process on SA/CMC-Ca-Al is characterized by FT-IR, SEM, EDX and XPS. The results show that Ca (II) and Al (III) are loaded on SA/CMC through ion-exchange of sodium of SA/CMC. The coordination reaction and ion-exchange happen during the adsorption process between SA/CMC-Ca-Al and uranium, fluoride. Results suggest that the SA/CMC-Ca-Al adsorbent has a great potential in removing uranium and fluoride from aqueous solution.

  9. Fluoride glass fiber optics

    CERN Document Server

    Aggarwal, Ishwar D

    1991-01-01

    Fluoride Glass Fiber Optics reviews the fundamental aspects of fluoride glasses. This book is divided into nine chapters. Chapter 1 discusses the wide range of fluoride glasses with an emphasis on fluorozirconate-based compositions. The structure of simple fluoride systems, such as BaF2 binary glass is elaborated in Chapter 2. The third chapter covers the intrinsic transparency of fluoride glasses from the UV to the IR, with particular emphasis on the multiphonon edge and electronic edge. The next three chapters are devoted to ultra-low loss optical fibers, reviewing methods for purifying and

  10. A NOVEL BIO-WASTE INCORPORATED ALGINATE SORBENT FOR DE-FLUORIDATION OF WATER

    Directory of Open Access Journals (Sweden)

    Carmalin Sophia Ayyappan

    2015-09-01

    Full Text Available This study evaluates the feasibility of using tamarind (Tamarindus indica seed powder for de-fluoridation of fluoride contaminated water. Batch study confirmed that tamarind seeds in dry powder form could remove 87% of fluoride from water. This bio-sorbent can be used effectively in areas where fluoride concentrations are above the permissible limits of 1.5 mg·l-1 as per WHO Standard, 1984. Tamarind seed powder was incorporated in a matrix of sodium alginate and made into gel-beads. The beads were tested for de-fluoridation efficiency by conducting column studies. The effect of various factors, such as flow rate, retention time, and the number of runs on the efficacy of fluoride removal was also studied. The results revealed that flow rate did not seem to have much effect on the percentage fluoride removal but the fluoride concentration decreased drastically upon greater retention time and multiple runs.

  11. Discussion on feasibility of longdistance transportation proposal of anhydrous aluminum fluoride%长距离输送无水氟化铝可行性方案探讨

    Institute of Scientific and Technical Information of China (English)

    方志超; 王慧; 吴海峰

    2011-01-01

    无水氟化铝是一种流动性比较好的粉体物料,传统输送方式是通过管道负压或正压.鉴于多氟多化工股份有限公司生产实际出现的问题,提出多种输送无水氟化铝的方案,并对这些方案做了分析和对比.通过打破常规的输送方式的选择,确定了一种最佳的可行性方案.该方案同样可作为其他行业物料输送借鉴之用.%Anhydrous aluminium fluoride is a powder material with excellent fluidity. Traditional transportation method of this powder is by pipeline under vacuum or over pressure condition. Refer to the practical production operation of Do -Fluoride Chemical Co. fLtd. , various proposals for the anhydrous aluminium fluoride long-distance transportation were put forward and comparison and analysis were also made on those proposals. By breaking the conventional choice of mode of delivery , the most optimum proposal was finally confirmed. The optimum Proposal can be also used as a source of reference for the material transportation of other industries.

  12. Effect of fluoride additives on production and characterization of nano--Al2O3 particles

    Indian Academy of Sciences (India)

    F Mirjalili

    2014-12-01

    Nano--Al2O3 particles were synthesized by a sol–gel method using aqueous solutions of aluminum isopropoxide and 0.5 Maluminum nitrate. Sodium dodecylbenzenesulfonate (SDBS) was used as surfactant stabilizing agents. The solution was stirred for 48 h at 60 °C. The microstructural observation showed that surfactant with 48 h stirring time nanoscale -Al2O3 powder was produced at 1200 °C in the range of 20–30 nm in the presence of SDBS as a surfactant with 48 h stirring time. Temperature reduction of -Al2O3 formation has been achieved by introducing fluoride in the alumina precursor. The effects of ZnF2 additive and milling on the phase transformation as well as micrograph of the prepared -Al2O3 particles were investigated. The samples were characterized by different techniques such as X-ray diffraction, thermogravimetry analysis, differential scanning calorimetry, Fourier transform infrared spectra, scanning electron microscopy and transmission electron microscopy. Results indicated that using zinc fluoride (ZnF2) additive accompanied by milling led to retardation of the transformation temperature and modification of the alumina particle shape. The finest size for nonagglomerated nano-plate-like -Al2O3 particles (15–20 nm) was achieved at 950 °C.

  13. Removal of uranium and fluorine from wastewater by double-functional microsphere adsorbent of SA/CMC loaded with calcium and aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Liping [Department of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang, Sichuan 621010 (China); Lin, Xiaoyan, E-mail: lxy20100205@163.com [Department of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang, Sichuan 621010 (China); Engineering Research Center of Biomass Materials, Ministry of Education, Mianyang, Sichuan 621010 (China); Zhou, Xingbao [Department of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang, Sichuan 621010 (China); Luo, Xuegang [Department of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang, Sichuan 621010 (China); Engineering Research Center of Biomass Materials, Ministry of Education, Mianyang, Sichuan 621010 (China)

    2016-10-30

    Highlights: • A new method to load calcium and aluminum on alginate/carboxymethyl cellulose sodium. • SA/CMC-Ca-Al can respectively remove fluorine and uranium. • SA/CMC-Ca-Al shows a good adsorption capacity for fluorine and uranium. • Characterizations are used to research the adsorption mechanism of SA/CMC-Ca-Al. - Abstract: A novel dual functional microsphere adsorbent of alginate/carboxymethyl cellulose sodium composite loaded with calcium and aluminum (SA/CMC-Ca-Al) is prepared by an injection device to remove fluoride and uranium, respectively, from fluoro-uranium mixed aqueous solution. Batch experiments are performed at different conditions: pH, temperature, initial concentration and contact time. The results show that the maximum adsorption amount for fluoride is 35.98 mg/g at pH 2.0, 298.15 K concentration 100 mg/L, while that for uranium is 101.76 mg/g at pH 4.0, 298.15 K concentration 100 mg/L. Both of the adsorption process could be well described by Langmuir model. The adsorption kinetic data is fitted well with pseudo-first-order model for uranium and pseudo-second-order model for fluoride. Thermodynamic parameters are also evaluated, indicating that the adsorption of uranium on SA/CMC-Ca-Al is a spontaneous and exothermic process, while the removal of fluoride is non-spontaneous and endothermic process. The mechanism of modification and adsorption process on SA/CMC-Ca-Al is characterized by FT-IR, SEM, EDX and XPS. The results show that Ca (II) and Al (III) are loaded on SA/CMC through ion-exchange of sodium of SA/CMC. The coordination reaction and ion-exchange happen during the adsorption process between SA/CMC-Ca-Al and uranium, fluoride. Results suggest that the SA/CMC-Ca-Al adsorbent has a great potential in removing uranium and fluoride from aqueous solution.

  14. Comparative study of adsorbents for the removal of fluoride ions from water use and consumption in Mexico; Estudio comparativo de adsorbentes para la remocion de iones fluoruro del agua de uso y consumo en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Teutli S, E. A.

    2014-07-01

    system for removal of fluoride ions in water for human use and consumption and to determine the mechanisms of sorption. The materials were modified with aluminum by an electrochemical method and lanthanum by treating them with a solution of sodium hydroxide and lanthanum nitrate. The characterization of materials was done by X-ray diffraction, scanning electron microscopy, elemental analysis and specific area. (Author)

  15. Fluoride removal from diluted solutions by Donnan dialysis using full factorial design

    Energy Technology Data Exchange (ETDEWEB)

    Boubakri, Ali; Helali, Nawel; Tlili, Mohamed; Amor, Mohamed Ben [Center of Researches and Water Technologies, Soliman (Turkey)

    2014-03-15

    Excessive fluoride concentration in potable water can lead to fluorosis of teeth and bones. In the present study, Donnan dialysis (DD) is applied for the removal of fluoride ions from diluted sodium fluoride solutions. A four factor two level (2{sup 4}) full factorial design was used to investigate the influence of different physico-chemical parameters on fluoride removal efficiency (Y{sub F}) and fluoride flux (J{sub F}) through anion exchange membrane. The statistical design determines factors which have the important effects on Donnan dialysis performance and studies all interactions among the considered parameters. The four significant factors were initial fluoride concentration, feed flow rate, temperature and agitation speed. The experimental results and statistical analysis show that the temperature and agitation speed have positive effects on fluoride removal efficiency and the initial fluoride concentration has a negative effect. In the case of fluoride flux, feed flow rate and initial concentration are the main effect and all factors have a positive effect. The interaction between studied parameters was not negligible on two responses. A maximum fluoride removal of 75.52% was obtained under optimum conditions and the highest value of fluoride flux obtained was 2.4 mg/cm{sup 2}·h. Empirical regression models were also obtained and used to predict the flux and the fluoride removal profiles with satisfactory results.

  16. Metabolismo e distribuição do flúor em ovinos jovens tratados cronicamente com fluoreto de sódio Metabolism and distribution of fluor in lambs chronically treated with sodium fluoride

    Directory of Open Access Journals (Sweden)

    Andreane R. Filappi

    2008-02-01

    Full Text Available Este estudo teve por objetivo avaliar o metabolismo do flúor (F em ovinos. Para tanto, utilizaram-se 12 animais, com cinco meses de idade, os quais receberam como dieta base 3% do peso vivo de feno de alfafa e água ad libitum. Os animais foram divididos e constituíram um grupo Controle, que recebeu apenas sal iodado (5g de NaCl/animal + 0,2mg I/kg matéria seca e, um grupo Tratado, que recebeu sal iodado adicionado de fluoreto de sódio (4,7mg F/kg de peso corporal. Esses sais foram administrados via sonda oro-esofágica, diariamente por um período de 150 dias. Para análise de F, coletaram-se amostras de sangue, urina e fezes e, ao fim do período experimental, após a eutanásia dos animais, coletou-se a glândula pineal e amostras de osso. Também nesta ocasião, coletou-se uma amostra de rim para exame histopatológico. Analisando-se os teores séricos, urinários e ósseos de F, verificou-se que foram significativamente superiores nos animais Tratados em relação aos Controles. Quanto ao F contido na glândula pineal, não houve diferença significativa entre os grupos. Na análise histológica do rim, não foram observadas alterações. Conclui-se que a administração crônica de flúor induz ao acúmulo desse elemento nos ossos, mesmo havendo um alto teor de cálcio na alimentação e esse acúmulo parece não ser nocivo aos animais. Em ovinos, a capacidade orgânica de acúmulo ósseo e excreção urinária do flúor é diferente de outras espécies animais.The objective of the present study was to evaluate fluorine metabolism in growing lambs. Twelve 5-month-old male lambs maintained on alfalfa hay (3% BW and non-fluorinated water ad libitum were used. Animals were allocated into Control, receiving 5g NaCl/animal/day + 0.2mg I/kg dry matter and Treated group, receiving the same treatment plus sodium fluoride (4.7mg F/kg body weight. Mineral treatment was given by gavage, daily for 150 days. Blood, urine and fecal samples were

  17. Fluoride Rinses, Gels and Foams

    DEFF Research Database (Denmark)

    Twetman, Svante; Keller, Mette K

    2016-01-01

    AIM: The aim of this conference paper was to systematically review the quality of evidence and summarize the findings of clinical trials published after 2002 using fluoride mouth rinses, fluoride gels or foams for the prevention of dental caries. METHODS: Relevant papers were selected after...... (6 on fluoride mouth rinse, 10 on fluoride gel and 3 on fluoride foam); 6 had a low risk of bias while 2 had a moderate risk. All fluoride measures appeared to be beneficial in preventing crown caries and reversing root caries, but the quality of evidence was graded as low for fluoride mouth rinse......, moderate for fluoride gel and very low for acidulated fluoride foam. No conclusions could be drawn on the cost-effectiveness. CONCLUSIONS: This review, covering the recent decade, has further substantiated the evidence for a caries-preventive effect of fluoride mouth rinse, fluoride gel and foam...

  18. PRODUCTION OF THORIUM FLUORIDE

    Science.gov (United States)

    Zachariasen, W.H.

    1959-08-11

    A process is presented for producing anhydrous thorium fluoride comprising the step of contacting a saturated aqueous solution of thorium nitrate with an aqueous solution of hydrofluoric acid having a concentration of about 45 to 50% by weight at a temperature above 70 deg C whereby anhydrous thorium fluoride precipitates.

  19. Determination of Boron Trifluoride in Boron Trifluoride Complex by Fluoride Ion Selective Electrode

    Institute of Scientific and Technical Information of China (English)

    郎五可; 张卫江; 唐银; 徐姣; 张雷

    2016-01-01

    A method was proposed to determine boron trifluoride in boron trifluoride complex using fluoride ion selective electrode(ISE). Hydroxide was chosen to mask aluminum for the determination of 0.01—0.1 mol/L of fluoride. The simulation indicated that the permissible aluminum masked at a certain pH value was limited and hardly related to F-concentration and boric acid. It is better to control pH value below 11.5 and the aluminum con-centration within 0.025 mol/L to minimize the interference of hydroxide to the fluoride ISE. The decomposition conditions of boron trifluoride by aluminum chloride were investigated. It is found that the F-detection ratio will approach 1.0 if the Al/F molar ratio is 0.3—0.7 and aluminum concentration is no more than 0.02 mol/L when heated at 80℃ for 10 min. In one word, hydroxide is quite fit to mask aluminum for samples which contain high content of fluoride and aluminum and the BF3 content can be successfully determined by this method.

  20. A prospective, randomized placebo-controlled clinical trial on the effects of a fluoride rinse on white spot lesion development and bleeding in orthodontic patients

    NARCIS (Netherlands)

    van der Kaaij, N.C.W.; van der Veen, M.H.; van der Kaaij, M.A.E.; ten Cate, J.M.

    2015-01-01

    Demineralizations around orthodontic brackets are a main disadvantage of orthodontic treatment. Several methods have been advocated to prevent their development, such as fluoride rinses or varnishes. In this randomized clinical trial, a fluoride rinse (a combination of sodium fluoride and amine fluo

  1. Histochemical investigations on the in vivo effects of fluoride on tricarboxylic acid cycle dehydrogenases from Pelargonium zonale. Part II

    Energy Technology Data Exchange (ETDEWEB)

    Lovelace, C.J.; Miller, G.W.

    1967-01-01

    In vivo effects of fluoride on tricarboxylic acid (TCA) cycle dehydrogenase enzymes of Pelargonium zonale were studied using p-nitro blue tetrazoleum chloride. Plants were exposed to 17 ppb HF, and enzyme activities in treated plants were compared to those in controls. Leaves of control plants were incubated in 5 x 10/sup -3/ M sodium fluoride. Injuries observed in fumigation and solution experiments were similar. Leaf tissue subjected to HF or sodium fluoride evidenced less succinic p-nitro blue tetrazoleum reductase activity than did control tissue. Other TCA cycle dehydrogenase enzymes were not observably affected by the fluoride concentrations used in these experiments. Excised leaves cultured in 5 x 10/sup -3/ M sodium fluoride exhibited less succinic p-nitro blue tetrazoleum reductase activity after 24 hr than did leaves cultured in 5 x 10/sup -3/ M sodium chloride. 8 references, 8 figures.

  2. Fluoride varnishes and enamel caries

    NARCIS (Netherlands)

    Bruyn, Hugo de

    1987-01-01

    Topical fluoride applications have the aim of increasing the fluoride uptake in enamel and consequently reducing caries. In the early ‘60s fluoride varnishes were introduced because they had a long contact period with the enamel which resulted in a higher fluoride uptake than from other topical appl

  3. Fluoride caused thyroid endocrine disruption in male zebrafish (Danio rerio).

    Science.gov (United States)

    Jianjie, Chen; Wenjuan, Xue; Jinling, Cao; Jie, Song; Ruhui, Jia; Meiyan, Li

    2016-02-01

    Excessive fluoride in natural water ecosystem has the potential to detrimentally affect thyroid endocrine system, but little is known of such effects or underlying mechanisms in fish. In the present study, we evaluated the effects of fluoride on growth performance, thyroid histopathology, thyroid hormone levels, and gene expressions in the HPT axis in male zebrafish (Danio rerio) exposed to different determined concentrations of 0.1, 0.9, 2.0 and 4.1 M of fluoride to investigate the effects of fluoride on thyroid endocrine system and the potential toxic mechanisms caused by fluoride. The results indicated that the growth of the male zebrafish used in the experiments was significantly inhibited, the thyroid microtrastructure was changed, and the levels of T3 and T4 were disturbed in fluoride-exposed male fish. In addition, the expressional profiles of genes in HPT axis displayed alteration. The expressions of all studied genes were significantly increased in all fluoride-exposed male fish after exposure for 45 days. The transcriptional levels of corticotrophin-releasing hormone (CRH), thyroid-stimulating hormone (TSH), thyroglobulin (TG), sodium iodide symporter (NIS), iodothyronine I (DIO1), and thyroid hormone receptor alpha (TRα) were also elevated in all fluoride-exposed male fish after 90 days of exposure, while the inconsistent expressions were found in the mRNA of iodothyronineⅡ (DIO2), UDP glucuronosyltransferase 1 family a, b (UGT1ab), transthyretin (TTR), and thyroid hormone receptor beta (TRβ). These results demonstrated that fluoride could notably inhibit the growth of zebrafish, and significantly affect thyroid endocrine system by changing the microtrastructure of thyroid, altering thyroid hormone levels and endocrine-related gene expressions in male zebrafish. All above indicated that fluoride could pose a great threat to thyroid endocrine system, thus detrimentally affected the normal function of thyroid of male zebrafish.

  4. 碳酸钠焙烧铝系钒铁炉渣共提取钒与铝%Recovery of Vanadium and Aluminum in Ferrovanadium Slag from Thermite Method by Sodium Carbonate-roasting

    Institute of Scientific and Technical Information of China (English)

    高明磊; 陈东辉; 石立新; 李兰杰; 周冰晶; 祁健

    2012-01-01

    通过对铝系钒铁炉渣碳酸钠焙烧-水浸全过程的矿物分析、热力学计算及对比实验,研究了炉渣中钒、铝同步转化、溶出的机理与规律.结果显示,焙烧进程中渣中镁铝尖晶石MgO·Al2O3相、CaO·2Al2O3相逐渐消失,MgO相生成,并生成碱熔相Na2O·Al2O3和钒酸盐.随焙烧温度及时间增加,Na2O·Al2O3和钒酸盐相明显增多,钒、铝溶出率增加.焙烧熟料经水浸后,液相呈碱性,钒、铝分别以可溶性钒酸钠和铝酸钠的形式进入水相,固相残留物为少量未反应的镁铝尖晶石及新生成的MgO和Ca(OH)2.在磨矿粒度<75μm、配碱系数1.0、焙烧温度1 000℃及焙烧时间4h的优化条件下,钒的溶出率可达90%,铝的溶出率可达75%.%By mineralogical analysis, thermodynamic calculation, and comparative experiments, the synchronous conversion of vanadium and aluminum was studied, and dissolving mechanism in the process of sodium carbonate roasting and water leaching on ferrovanadium slag. The results showed that magnesia-alumina spinel (MgO-Al2O3) and CaO-2Al2O3 phases gradually disappeared, and MgO phase, alkali melting phase of Na2O-Al2O3 and phase vanadate were generated in the roasting process. Na2O-Al2O3 and vanadate phases increased obviously with the increase of roasting temperature and time, resulting in the dissolution increase of vanadium and aluminum. Vanadium and aluminum, in vanadate and sodium aluminate, could be dissolved into water solution, as the solution was alkaline when the clinker was leached by water. The solid residues were a small amount of unreacted magnesia-alumina spinel and new generated MgO and Ca(OH)2. The optimum roasting conditions were obtained as follows: grinding particle size below 75 μm, molar ratio of Al2O3 and V2O5 to Na2CO3 1:1, roasting temperature 1000 ℃and roasting time 4 h. Under these conditions, the leaching rates of vanadium and aluminum were up to 90% and 75%, respectively.

  5. Effect of sodium injection rate in reduction process on characteristics of tantalum powders

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The paper presents a research the effect of sodium injection rate in a melt containing potassium tantalum fluoride and a flux on morphology and characteristics of tantalum powders obtained by sodium reduction.

  6. Salt fluoridation and oral health

    OpenAIRE

    Thomas M. Marthaler

    2013-01-01

    The aim of this paper is to make known the potential of fluoridated salt in community oral health programs, particularly in South Eastern Europe. Since 1922, the addition of iodine to salt has been successful in Switzerland. Goiter is virtually extinct. By 1945, the cariesprotective effect of fluorides was well established. Based on the success of water fluoridation, a gynecologist started adding of fluoride to salt. The sale of fluoridated salt began in 1956 in the Swiss Canton of Zurich,...

  7. Innovative Monitoring of Atmospheric Gaseous Hydrogen Fluoride

    Science.gov (United States)

    Bonari, Alessandro; Pompilio, Ilenia; Monti, Alessandro; Arcangeli, Giulio

    2016-01-01

    Hydrogen fluoride (HF) is a basic raw material for a wide variety of industrial products, with a worldwide production capacity of more than three million metric tonnes. A novel method for determining particulate fluoride and gaseous hydrogen fluoride in air is presented herewith. Air was sampled using miniaturised 13 mm Swinnex two-stage filter holders in a medium-flow pumping system and through the absorption of particulate fluoride and HF vapours on cellulose ester filters uncoated or impregnated with sodium carbonate. Furthermore, filter desorption from the holders and the extraction of the pentafluorobenzyl ester derivative based on solid-phase microextraction were performed using an innovative robotic system installed on an xyz autosampler on-line with gas chromatography (GC)/mass spectrometry (MS). After generating atmospheres of a known concentration of gaseous HF, we evaluated the agreement between the results of our sampling method and those of the conventional preassembled 37 mm cassette (±8.10%; correlation coefficient: 0.90). In addition, precision (relative standard deviation for n = 10, 4.3%), sensitivity (0.2 μg/filter), and linearity (2.0–4000 μg/filter; correlation coefficient: 0.9913) were also evaluated. This procedure combines the efficiency of GC/MS systems with the high throughput (96 samples/day) and the quantitative accuracy of pentafluorobenzyl bromide on-sample derivatisation. PMID:27829835

  8. Innovative Monitoring of Atmospheric Gaseous Hydrogen Fluoride

    Directory of Open Access Journals (Sweden)

    Stefano Dugheri

    2016-01-01

    Full Text Available Hydrogen fluoride (HF is a basic raw material for a wide variety of industrial products, with a worldwide production capacity of more than three million metric tonnes. A novel method for determining particulate fluoride and gaseous hydrogen fluoride in air is presented herewith. Air was sampled using miniaturised 13 mm Swinnex two-stage filter holders in a medium-flow pumping system and through the absorption of particulate fluoride and HF vapours on cellulose ester filters uncoated or impregnated with sodium carbonate. Furthermore, filter desorption from the holders and the extraction of the pentafluorobenzyl ester derivative based on solid-phase microextraction were performed using an innovative robotic system installed on an xyz autosampler on-line with gas chromatography (GC/mass spectrometry (MS. After generating atmospheres of a known concentration of gaseous HF, we evaluated the agreement between the results of our sampling method and those of the conventional preassembled 37 mm cassette (±8.10%; correlation coefficient: 0.90. In addition, precision (relative standard deviation for n=10, 4.3%, sensitivity (0.2 μg/filter, and linearity (2.0–4000 μg/filter; correlation coefficient: 0.9913 were also evaluated. This procedure combines the efficiency of GC/MS systems with the high throughput (96 samples/day and the quantitative accuracy of pentafluorobenzyl bromide on-sample derivatisation.

  9. Urinary fluoride excretion after application of fluoride varnish and use of fluoride toothpaste in young children

    DEFF Research Database (Denmark)

    Lockner, Frida; Twetman, Svante; Stecksén-Blicks, Christina

    2017-01-01

    the levels with and without parallel use of fluoride toothpaste. DESIGN: Fifteen healthy children were enrolled to a randomized crossover trial that was performed in two parts: Part I with twice-daily tooth brushing with fluoride toothpaste and Part II with twice-daily brushing with a non-fluoride toothpaste......: There was a statistically significant increase in the 6-h fluoride excretion after application of both experimental varnishes, with and without parallel use of fluoride toothpaste (P toothpaste was used, the mean fluoride excretion was 0.20 mg/6 h after application of Duraphat and 0.29 mg/6 h...... after application of Profluorid Varnish (P = 0.18). CONCLUSIONS: Topical applications of 0.1 mL of fluoride varnish significantly increased the 6-h fluoride excretion. As some individuals displayed excretion levels exceeding the optimal fluoride exposure, a restricted use of fluoride toothpaste...

  10. Influence of milk products on fluoride bioavailability in man.

    Science.gov (United States)

    Ekstrand, J; Ehrnebo, M

    1979-09-01

    The effect of milk products on the gastrointestinal absorption of fluoride from sodium fluoride tablets was studied in five healthy subjects. Two different diets were tested: (1) 250 ml standardized milk (3% fat) and (2) 500 ml of milk, 3 pieces of white bread with cheese and 150 ml of yoghurt. The 100% bioavailability of sodium fluoride tablets during fasting was greatly decreased by coadministration of milk products: with Diet 1 the absolute bioavailability calculated from combined plasma and urine data was in the range 50--79% and with Diet 2 it ranged from 50--71%. It is suggested that the decreased bioavailability produced by dairy products should be taken into account when establishing flouride dosage regimens for prophylaxis of caries.

  11. COMPARATIVE STUDY OF GREEN TEA POLYPHENOL AND FLUORIDE ON STREPTOCOCCUS MUTANS

    Institute of Scientific and Technical Information of China (English)

    李鸣宇; 刘正

    2000-01-01

    Objective To disclose the mechanism of green tea polyphenol in the prevention of dental caries.Methods Using sodium fluoride (highly effective anticaries agent) as control and Streptococcus mutans (carigenous microbe) as target, green tea polyphenol (potential bacterial inhibitor) was used to testify its action on the change of microbial morphology, extramicrobial sucrase, glucosyltransferase (GTF), lactate hydrogenase (LDH),protein and pH values of the culture media. Results GTF activities were inhibited both by green tea polyphenol and sodium fluoride, the inhibitory efficacy was stronger in green tea polyphenol. Morphologic changes consisted of membrane disruption in tea polyphenol treated microbes, and cytoplasmic vacuolization in fluoride treated bacteria.High protein level in fluoride treated culture media means cytoplasmic decomposition, intracellular protein leakage into media. Conclusion The inhibition of GTF activity was stronger in green tea polyphenol treated microbes.The target of action was cell membrane disruption in green tea polyphenol treated cell and cytoplasmic in fluoride treated microbes.

  12. Effect of fluoride and chlorhexidine digluconate mouthrinses on plaque biofilms

    DEFF Research Database (Denmark)

    Rabe, Per; Twetman, Svante; Kinnby, Bertil;

    2015-01-01

    in the pre-molar region were worn by three subjects for 7 days. Control discs were removed before subjects rinsed with 0.1% chlorhexidine digluconate (CHX) or 0.2% sodium fluoride (NaF) for 1 minute. Biofilms were stained with Baclight Live/Dead and z-stacks of images created using confocal scanning laser...

  13. Simultaneous determination of NaOH, Na2CO3 and Al2O3 in sodium aluminate solutions by flow injection titration

    Institute of Scientific and Technical Information of China (English)

    陈晓青; 方彩云; 张心英; 张磊

    2001-01-01

    A flow injection titration method for simultaneous determination of hydroxide, carbonate and alumina in sodium aluminate solutions was proposed. 150μL sample was injected and firstly reacted with a mixture of methyl orange, phenolphthalein and sulfosalicylic acid, and secondly, a mixture of chlorhydric acid, ammonium fluoride and phenolphthalein. Methyl orange and phenolphthalein in the first are the corresponding indicators for the determination of hydroxide and carbonate; sulfosalicylic acid is both the titrant and masking agent for aluminum. Ammonium fluoride in the second is complexing agent for alumina and makes it release corresponding amounts of hydroxide ion to aluminum; phenolphthalein is the corresponding indicator for the determination of hydroxide, carbonate and alumina. Chlorhydric acid is the titrant agent for the three. The proposed method can be employed to analyze aluminate solutions containing hydroxide 3.1~15.5g/L-1, carbonate 3.1~15.5g/L-1 and alumina 0.51~1.02g/L-1 with a sampling frequency of 30 samples per hour. 0.54% and 0.89% are the RSD of sodium oxide and of alumina respectively (n=11).

  14. Composite Gel Polymer Electrolyte Based on Poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) with Modified Aluminum-Doped Lithium Lanthanum Titanate (A-LLTO) for High-Performance Lithium Rechargeable Batteries.

    Science.gov (United States)

    Le, Hang T T; Ngo, Duc Tung; Kalubarme, Ramchandra S; Cao, Guozhong; Park, Choong-Nyeon; Park, Chan-Jin

    2016-08-17

    A composite gel polymer electrolyte (CGPE) based on poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) polymer that includes Al-doped Li0.33La0.56TiO3 (A-LLTO) particles covered with a modified SiO2 (m-SiO2) layer was fabricated through a simple solution-casting method followed by activation in a liquid electrolyte. The obtained CGPE possessed high ionic conductivity, a large electrochemical stability window, and interfacial stability-all superior to that of the pure gel polymer electrolyte (GPE). In addition, under a highly polarized condition, the CGPE effectively suppressed the growth of Li dendrites due to the improved hardness of the GPE by the addition of inorganic A-LLTO/m-SiO2 particles. Accordingly, the Li-ion polymer and Li-O2 cells employing the CGPE exhibited remarkably improved cyclability compared to cells without CGPE. In particular, the CGPE as a protection layer for the Li metal electrode in a Li-O2 cell was effective in blocking the contamination of the Li electrode by oxygen gas or impurities diffused from the cathode side while suppressing the Li dendrites.

  15. Effect of fluoride toothpastes on enamel demineralization

    Directory of Open Access Journals (Sweden)

    Gintner Zeno

    2006-06-01

    Full Text Available Abstract Background It was the aim of this study to investigate the effect of four different toothpastes with differing fluoride compounds on enamel remineralization. Methods A 3 × 3 mm window on the enamel surface of 90 human premolars was demineralized in a hydroxyethylcellulose solution at pH 4.8. The teeth were divided into 6 groups and the lower half of the window was covered with varnish serving as control. The teeth were immersed in a toothpaste slurry containing: placebo tooth paste (group 1; remineralization solution (group 2; Elmex Anticaries (group 3; Elmex Sensitive (group 4; Blend-a-med Complete (group 5 and Colgate GRF (group 6. Ten teeth of each group were used for the determination of the F- content in the superficial enamel layer and acid solubility of enamel expressed in soluble phosphorus. Of 6 teeth of each group serial sections were cut and investigated with polarization light microscopy (PLM and quantitative energy dispersive X-ray analysis (EDX. Results The PLM results showed an increased remineralization of the lesion body in the Elmex Anticaries, Elmex Sensitive and Colgate GRF group but not in the Blend-a-med group. A statistically significant higher Ca content was found in the Elmex Anticaries group. The fluoride content in the superficial enamel layer was significantly increased in both Elmex groups and the Blend-a-med group. Phosphorus solubility was significantly decreased in both Elmex groups and the Blend-a-med group. Conclusion It can be concluded that amine fluoride compounds in toothpastes result in a clearly marked remineralization of caries like enamel lesions followed by sodium fluoride and sodium monofluorophosphate formulations.

  16. Fluoride retention by kaolin clay

    DEFF Research Database (Denmark)

    Kau, P. M. H.; Smith, D. W.; Binning, Philip John

    1997-01-01

    To evaluate the potential effectiveness of kaolin clay liners in storage of fluoride contaminated waste, an experimental study of the sorption and desorption behaviour of fluoride in kaolin clay was conducted. The degree of fluoride sorption by kaolin was found to depend on solution p......H and available fluoride concentration with equilibrium being achieved within 24 h. A site activation process involving the uptake of fluoride was also observed at the initial stages of sorption. This behaviour was attributed to a layer expansion process of the clay during sorption. The maximum fluoride sorption...

  17. Water Fluoridation Statistics - Percent of PWS population receiving fluoridated water

    Data.gov (United States)

    U.S. Department of Health & Human Services — 2000-2014. Water Fluoridation Statistics is a biennial report of the percentage and number of people receiving fluoridated water from 2000 through 2014, originally...

  18. Water Fluoridation Statistics - Percent of PWS population receiving fluoridated water

    Data.gov (United States)

    U.S. Department of Health & Human Services — 2000-2014 Water Fluoridation Statistics is a biennial report of the percentage and number of people receiving fluoridated water from 2000 through 2014, originally...

  19. Fluoride in the drinking water of Pakistan and the possible risk of crippling fluorosis

    Directory of Open Access Journals (Sweden)

    M. A. Tahir

    2013-02-01

    Full Text Available To explore the possibility of fluoride toxicity, 747 water samples were collected from surface water and groundwater sources of 16 major cities of Pakistan, adopting a uniform sampling design with distribution of samples: Lahore (79, Kasur (46, Faisalabad (30, Khushab (50, Chakwal (51, Mianwali (30, Jhelum (53, Bahawalpur (60, Karachi (60, Mirpur Khas (55, Peshawar (38, Risalpur (35, Quetta (81, Ziarat (21, Loralai (21, and Mastung (37. Comparison of analytical findings with WHO Guidelines of Drinking Water for Fluoride (i.e., 1.5 ppm has concluded that 16% of the monitored water sources have fluoride concentration beyond the permissible safe limit of 1.5 mg L−1 falling in the concentration range of 1.6–25 mg L−1. The highest fluoride contamination (22% is detected in the Balochistan province followed by 19% in Punjab province. Comparatively higher fluoride levels of > 20% in the groundwater sources like hand pumps supported the possibility of increased groundwater contamination as excessive fluoride concentrations are expected to come from calcium-poor aquifers and in areas where fluoride-bearing minerals are common or where cation exchange of sodium for calcium occurs. Field observations have also indicated the prevalence of fluoride-associated health implications in the study areas with excessive fluoride in water sources. Findings of this study have provided bidirectional vision for the epidemiological investigations as well as to mitigate the issues in the affected vicinities of fluoride-rich areas.

  20. Shock wave compression behavior of aluminum foam

    Institute of Scientific and Technical Information of China (English)

    程和法; 黄笑梅; 薛国宪; 韩福生

    2003-01-01

    The shock wave compression behavior of the open cell aluminum foam with relative density of 0. 396 was studied through planar impact experiments. Using polyvinylidene fluoride(PVDF) piezoelectric gauge technique, the stress histories and propagation velocities of shock wave in the aluminum foam were measured and analyzed. The results show that the amplitude of shock wave attenuates rapidly with increasing the propagation distance in the aluminum foam, and an exponential equation of the normalized peak stress vs propagation distance of shock wave is established, the attenuation factor in the equation is 0. 286. Furthermore, the Hugoniot relation, νs = 516.85+ 1.27νp,for the aluminum foam is determined by empirical fit to the experimental Hugoniot data.

  1. Permeability and fluoride release of lining materials containing amine fluorides.

    Science.gov (United States)

    Nordbö, H; Eriksen, H M

    1976-11-01

    The addition of amine fluorides to a copal recin (Copalite) and a chlorine caoutchouc varnish (Pergut S-40) has been studied. The permeability of Copalite films was only slightly increased whereas the excellent film-forming qualities of Pergut S-40 were destroyed by the addition of fluorides. A high fluoride release was found initially from test films of the materials but within 2-3 weeks a decrease to very low fluoride levels was observed.

  2. Status of industrial fluoride pollution and its diverse adverse health effects in man and domestic animals in India.

    Science.gov (United States)

    Choubisa, Shanti Lal; Choubisa, Darshana

    2016-04-01

    Hydrofluorosis in humans and domestic animals is a worldwide health problem and caused by a prolonged period of fluoride exposure through drinking of fluoride contaminated water. But in recent years, due to rapid industrialization in India, diverse serious health problems among industrial workers and residents and domestic animals living in the industrial areas due to fluoride pollution are on the rise. A number of coal-burning and industrial activities such as power-generating stations, welding operations and the manufacturing or production of steel, iron, aluminum, zinc, phosphorus, chemical fertilizers, bricks, glass, plastic, cement, and hydrofluoric acid are generally discharging fluoride in both gaseous and particulate/dust forms into surrounding environments which create a industrial fluoride pollution and are an important cause of occupational exposure to fluoride in several countries including India. An industrial emitted fluoride contaminates not only surrounding soil, air, and water but also vegetation, crops and many other biotic communities on which man and animals are generally dependants for food. Long- time of inhalation or ingestion of industrial fluoride also causes serious health problems in the forms of industrial and neighborhood fluorosis. In India, whatever research works conducted so far on the chronic industrial fluoride intoxication or poisoning (industrial and neighborhood fluorosis) in man and various species of domestic animals due to a prolonged period of industrial fluoride exposure or pollution (contamination) are critically reviewed in the present communication. Simultaneously, we are also focused the various bio-indicators and bio-markers for chronic industrial fluoride intoxication or pollution.

  3. Indices of atmospheric purity and fluoride pollution pattern in Arvida, Quebec

    Energy Technology Data Exchange (ETDEWEB)

    LeBlanc, F.; Rao, D.N.; Comeau, G.

    1972-01-01

    Indices of atmospheric purity (IAP) of 42 sites located in all directions from the aluminum factory at Arvida and spread out in about 250-km/sup 2/ area, were determined on the basis of phytosociology of epiphytes of Populus balsamifera. These index values ranging from 0 to 103 were arranged into six groups and the investigated area was accordingly delineated into six IAP zones to represent areas with different levels of fluoride pollution. A relative picture of the approximate limits of fluoride contamination in different zones is obtained by the fluoride accumulation in Parmelia sulcata thalli transplanted at various sites in the area.

  4. Delayed tooth replantation after root surface treatment with sodium hypochlorite and sodium fluoride: histomorphometric analysis in rats Reimplante dentário tardio após o tratamento da superfície radicular com hipoclorito de sódio e fluoreto de sódio: análise histomorfométrica em ratos

    Directory of Open Access Journals (Sweden)

    André Dotto Sottovia

    2006-04-01

    Full Text Available In cases of delayed tooth replantation, non-vital periodontal ligament remnants have been removed with sodium hypochlorite in an attempt to control root resorption. Nevertheless, reports of its irritating potential in contact with the alveolar connective tissue have been described. Therefore, this study evaluated the healing process on delayed replantation of rat teeth, after periodontal ligament removal by different treatment modalities. Twenty-four rats, assigned to 3 groups (n=8, had their upper right incisor extracted and left on the workbench for desiccation during 60 min. Afterwards, the teeth in group I were immersed in saline for 2 min. In group II, root surfaces were scrubbed with gauze soaked in saline for 2 min; and in group III, scrubbing was done with gauze soaked in 1% sodium hypochlorite solution. Thereafter, root surfaces were etched with 37% phosphoric acid and immersed in 2% acidulate-phosphate sodium fluoride solution, at pH 5.5. Root canals were filled with a calcium hydroxide-based paste and the teeth were replanted. The animals were sacrificed 60 days postoperatively and the pieces containing the replanted teeth were processed and paraffin- embedded. Semi-serial transversally sections were obtained from the middle third of the root and stained with hematoxylin and eosin for histomorphometric analysis. Data were analyzed statistically using Kruskal-Wallis and Dunn's tests. The results showed that root structure and cementum extension were more affected by resorption in group III (pEm reimplante dentário tardio, o ligamento periodontal desvitalizado tem sido removido empregando-se o hipoclorito de sódio, buscando o controle da reabsorção radicular. Relatos de efeito irritante no tecido conjuntivo alveolar após o seu uso, têm sido descritos. Isso justificou a realização deste trabalho buscando minimizar esse inconveniente. Para isso 24 ratos, divididos em 3 grupos de 8 animais, tiveram o incisivo superior direito extra

  5. Arsenic and fluoride removal from groundwater by electrocoagulation using a continuous filter-press reactor.

    Science.gov (United States)

    Guzmán, Athziri; Nava, José L; Coreño, Oscar; Rodríguez, Israel; Gutiérrez, Silvia

    2016-02-01

    We investigated simultaneous arsenic and fluoride removal from ground water by electrocoagulation (EC) using aluminum as the sacrificial anode in a continuous filter-press reactor. The groundwater was collected at a depth of 320 m in the Bajío region in Guanajuato Mexico (arsenic 43 µg L(-1), fluoride 2.5 mg L(-1), sulfate 89.6 mg L(-1), phosphate 1.8 mg L(-1), hydrated silica 112.4 mg L(-1), hardness 9.8 mg L(-1), alkalinity 31.3 mg L(-1), pH 7.6 and conductivity 993 µS cm(-1)). EC was performed after arsenite was oxidized to arsenate by addition of 1 mg L(-1) hypochlorite. The EC tests revealed that at current densities of 4, 5 and 6 mA cm(-2) and flow velocities of 0.91 and 1.82 cm s(-1), arsenate was abated and residual fluoride concentration satisfies the WHO standard (CF < 1.5 mg L(-1)). Spectrometric analyses performed on aluminum flocs indicated that these are mainly composed of aluminum-silicates of calcium and magnesium. Arsenate removal by EC involves adsorption on aluminum flocs, while fluoride replaces a hydroxyl group from aluminum aggregates. The best EC was obtained at 4 mA cm(-2) and 1.82 cm s(-1) with electrolytic energy consumption of 0.34 KWh m(-3).

  6. Heavy Metal Fluoride Glasses.

    Science.gov (United States)

    1987-04-01

    i 2N E ihhhhh1112h MEmhhhhEEEohhhhE I.’....momo 111111111’-20 LA ’Ll2. AFWL-TR-86-37 AFWL-TR- 86-37 oT C ,l C ’-’ N HEAVY METAL FLUORIDE GLASSES 0nI...Secwrit CkasmfcationJ HEAVY METAL FLUORIDE GLASSES 12. PERSONAL AUTHOR(S) Reisfield, Renata; and Eyal, Mrek 13. TYPE OF REPORT 113b. TIME COVERED 114...glasses containing about 50 mole% of ZrF4 [which can be replaced by HfF 4 or TIF 4 (Refs. 1-3) or heavy metal fluorides based on PbF2 and on 3d-group

  7. Fluoride Rinses, Gels and Foams

    DEFF Research Database (Denmark)

    Twetman, Svante; Keller, Mette K

    2016-01-01

    AIM: The aim of this conference paper was to systematically review the quality of evidence and summarize the findings of clinical trials published after 2002 using fluoride mouth rinses, fluoride gels or foams for the prevention of dental caries. METHODS: Relevant papers were selected after an el...... brushing with fluoride toothpaste....

  8. Acceptability of Salt Fluoridation in a Rural Latino Community in the United States: An Ethnographic Study.

    Directory of Open Access Journals (Sweden)

    Judith C Barker

    Full Text Available Compared to other population groups in the United States, caries (tooth decay is a disproportionately prevalent disease among Latino populations, especially among low-income and rural sub-groups and children under five years of age. Fluoride is a primary preventive for caries. While water fluoridation is a major and effective public health means for delivering fluoride on a mass scale, it does not reach many rural areas or population groups such as Latinos who eschew drinking water from municipal sources. This study examines the acceptability to such groups of salt fluoridation, an alternate means of delivering fluoride long used on a global scale. An ethnographic study in California's rural Central Valley was performed. Thirty individual interviews and 5 focus groups (N = 61 were conducted in Spanish to investigate low-income Latino migrant caregivers' experiences, views and understandings of domestic salt, oral health, caries prevention and fluoride. Audio data were transcribed, translated, coded and thematically analyzed. Table salt was readily available and frequently consumed. Both adult and child daily sodium consumption was high. Despite a general feeling that it was good, and present in dentifrices or dietary supplements, most participants had little knowledge about fluoride. Concerns were raised about cardio-vascular and other possibly deleterious effects if an increase in salt consumption occurred because fluoridated salt was viewed as having 'extra' benefits. Once informed about fluoride's safety and role in caries prevention, most participants expressed willingness to use fluoridated salt, especially if it benefitted children. Reassurance about its safety and benefits, and demonstration of its taste, were important aspects of acceptance. Taste was paramount. Participants would not consume more fluoridated salt than their current salt as that would result in unpleasant changes in food flavor and taste. While salt fluoridation is

  9. Cariostatic effect of fluoride-containing restorative materials associated with fluoride gels on root dentin

    Directory of Open Access Journals (Sweden)

    Fernanda Tavares Borges

    2010-10-01

    Full Text Available Secondary caries is still the main cause of restoration replacement, especially on the root surface OBJECTIVE: This in vitro study evaluated the cariostatic effects of fluoride-containing restorative materials associated with fluoride gels, on root dentin. MATERIALS AND METHODS: A randomized complete block design was used to test the effects of the restorative systems, fluoride regimes and the interactions among them at different distances from restoration margins. Standardized cavities were prepared on 240 bovine root specimens and randomly assigned to 15 groups of treatments (n=16. Cavities were filled with the following restorative materials: Ketac-Fil (3M-ESPE; Vitremer (3M-ESPE; Dyract/Prime & Bond NT (Dentsply; Charisma/Gluma One Bond (Heraeus Kulzer and the control, Z250/Single Bond (3M-ESPE. The specimens were subjected to a pH-cycling model designed to simulate high-caries activity. During the cycles, 1.23% acidulated phosphate fluoride, 2.0% neutral sodium fluoride or deionized/distilled water (control was applied to the specimens for 4 min. The surface Knoop microhardness test was performed before (KHNi and after (KHNf the pH cycles at 100, 200 and 300 mm from the margins. Dentin microhardness loss was represented by the difference in initial and final values (KHNi - KHNf. Data were analyzed by Friedman's and Wilcoxon's tests, ANOVA and Tukey's test (α=5%. RESULTS: The interaction of restorative systems and topical treatments was not significant (p=0.102. Dentin microhardness loss was lowest closer to the restoration. Ketac-fil presented the highest cariostatic effect. Vitremer presented a moderate effect, while Dyract and Charisma did not differ from the control, Z250. The effects of neutral and acidulated fluoride gels were similar to each other and higher than the control. CONCLUSION: Conventional and resin-modified glass ionomer cements as well as neutral and acidulated fluoride gels inhibit the progression of artificial caries

  10. The effects of a stannous-containing sodium fluoride dentifrice and crisscross bristle toothbrush in the management of gingivitis and dental plaque observed by an office-based study%新型亚锡-氟化钠牙膏和交叉刷毛牙刷减轻牙龈炎和清除牙菌斑效果研究

    Institute of Scientific and Technical Information of China (English)

    邱百灵; 常金兰; 何涛; 贺艳焱; 李昕; 吉宁; 孙丽丽; 韩南银

    2015-01-01

    Objective:To investigate the effects of a stannous-containing sodium fluoride dentifrice and crisscross bristle manual tooth-brush in the management of dental plaque and gingivitis.Methods:249 cases with gingivitis were enrolled in an office-based study. The study was unsupervised and single-centered with open-label and self-control.At baseline,gingival health and plaque coverage were assessed by dentists using categorical scales.Participants were given stannous containing sodium fluoride dentifrice and crisscross bristle design manual brush,and were instructed to use the products by manufacturer's usage instructions twice daily for 30 days.At the end of 30 days,plaque and gingivitis were reassessed using the same categorical scales.Results:232 participants(1 78 females and 54 males) completed the study.Gingivitis data of 5 cases and dental plaque data of 3 cases were not judgable.After 30 days of product use,226 cases(99%)showed noticeable improvement in their gingival health;227(96%)cases showed improvement in overnight plaque cover-age.Conclusion:Stannous-containing sodium fluoride dentifrice in combination with crisscross bristle toothbrush is effective in the management of gingivitis and dental plaque.%目的:观察新型亚锡-氟化钠牙膏和交叉刷毛牙刷减轻牙龈炎和清除牙菌斑效果。方法:纳入中度和重度牙龈炎及牙菌斑覆盖受访者,采用开放标签、单中心、自身前后对照试验。按厂家说明使用含亚锡-氟化钠系统的牙膏和交叉刷毛的牙刷每日刷牙2次,为期30 d。由专业牙科医师对受访者的牙龈健康和牙菌斑覆盖程度进行基线和终点标准化的评估。结果:纳入符合标准的受访者249名,平均年龄(31.37±7.24)岁。女性185名,男性64名。232名受访者完成了研究。5人牙龈炎数据不可评估,3人牙菌斑数据不可评估,226名(99%)受访者牙龈炎明显减轻,227名(96%)受访者隔夜牙菌

  11. Fluoride Rinses, Gels and Foams

    DEFF Research Database (Denmark)

    Twetman, Svante; Keller, Mette K

    2016-01-01

    AIM: The aim of this conference paper was to systematically review the quality of evidence and summarize the findings of clinical trials published after 2002 using fluoride mouth rinses, fluoride gels or foams for the prevention of dental caries. METHODS: Relevant papers were selected after...... an electronic search for literature published in English between 2003 and 2014. The included papers were assessed for their risk of bias and the results were narratively synthesized due to study heterogeneity. The quality of evidence was expressed according to GRADE. RESULTS: A total of 19 papers were included...... (6 on fluoride mouth rinse, 10 on fluoride gel and 3 on fluoride foam); 6 had a low risk of bias while 2 had a moderate risk. All fluoride measures appeared to be beneficial in preventing crown caries and reversing root caries, but the quality of evidence was graded as low for fluoride mouth rinse...

  12. Effects of Fluoride on Lipid Peroxidation, DNA Damage and Apoptosis in Human Embryo Hepatocytes

    Institute of Scientific and Technical Information of China (English)

    AI-GUO WANG; TAO XIA; QI-LONG CHU; MING ZHANG; FANG LIU; XUE-MIN CHEN; KE-DI YANG

    2004-01-01

    Objective To investigate the effects of fluoride on lipid peroxidation, DNA damage and apoptosis in human embryo hepatocyte L-02 cells. Methods Lipid peroxide (LPO) level, reduced glutathione (GSH) content, DNA damage, apoptosis, and cell cycle analysis were measured after in vitro cultured L-02 cells were exposed to sodium fluoride at different doses (40 μg/mL, 80 μg/mL, and 160 μg/mL) for 24 hours. Results Fluoride caused an increase of LPO levels and a decrease of GSH content in L-02 cells. There appeared to be an obvious dose-effect relationship between the fluoride concentration and the observed changes. Fluoride also caused DNA damage and apoptosis and increased the cell number in S phase of cell cycle in the cells tested. There was a statistically significant difference in DNA damage and apoptosis when comparing the high dose of fluoride treated cells with the low dose of fluoride treated cells. Conclusion Fluoride can cause lipid peroxidation, DNA damage, and apoptosis in the L-02 cell experimental model and there is a significant positive correlation between fluoride concentration and these pathological changes.

  13. Salt fluoridation and oral health

    Directory of Open Access Journals (Sweden)

    Thomas M. Marthaler

    2013-11-01

    Full Text Available The aim of this paper is to make known the potential of fluoridated salt in community oral health programs, particularly in South Eastern Europe. Since 1922, the addition of iodine to salt has been successful in Switzerland. Goiter is virtually extinct. By 1945, the cariesprotective effect of fluorides was well established. Based on the success of water fluoridation, a gynecologist started adding of fluoride to salt. The sale of fluoridated salt began in 1956 in the Swiss Canton of Zurich, and several other cantons followed suit. Studies initiated in the early seventies showed that fluoride, when added to salt, inhibits dental caries. The addition of fluoride to salt for human consumption was officially authorized in 1980-82. In Switzerland 85% of domestic salt consumed is fluoridated and 67% in Germany. Salt fluoridation schemes are reaching more than one hundred million in Mexico, Colombia, Peru and Cuba. The cost of salt fluoridation is very low, within 0.02 and 0.05 € per year and capita. Children and adults of the low socio-economic strata tend to have substantially more untreated caries than higher strata. Salt fluoridation is by far the cheapest method for improving oral health. Conclusions. Salt fluoridation has cariostatic potential like water fluoridation (caries reductions up to 50%. In Europe, meaningful percentages of users have been attained only in Germany (67% and Switzerland (85%. In Latin America, there are more than 100 million users, and several countries have arrived at coverage of 90 to 99%. Salt fluoridation is by far the cheapest method of caries prevention, and billions of people throughout the world could benefit from this method.

  14. Acceptability of Salt Fluoridation in a Rural Latino Community in the United States: An Ethnographic Study

    Science.gov (United States)

    Barker, Judith C.; Hoeft, Kristin S.

    2016-01-01

    Compared to other population groups in the United States, caries (tooth decay) is a disproportionately prevalent disease among Latino populations, especially among low-income and rural sub-groups and children under five years of age. Fluoride is a primary preventive for caries. While water fluoridation is a major and effective public health means for delivering fluoride on a mass scale, it does not reach many rural areas or population groups such as Latinos who eschew drinking water from municipal sources. This study examines the acceptability to such groups of salt fluoridation, an alternate means of delivering fluoride long used on a global scale. An ethnographic study in California’s rural Central Valley was performed. Thirty individual interviews and 5 focus groups (N = 61) were conducted in Spanish to investigate low-income Latino migrant caregivers’ experiences, views and understandings of domestic salt, oral health, caries prevention and fluoride. Audio data were transcribed, translated, coded and thematically analyzed. Table salt was readily available and frequently consumed. Both adult and child daily sodium consumption was high. Despite a general feeling that it was good, and present in dentifrices or dietary supplements, most participants had little knowledge about fluoride. Concerns were raised about cardio-vascular and other possibly deleterious effects if an increase in salt consumption occurred because fluoridated salt was viewed as having ‘extra’ benefits. Once informed about fluoride’s safety and role in caries prevention, most participants expressed willingness to use fluoridated salt, especially if it benefitted children. Reassurance about its safety and benefits, and demonstration of its taste, were important aspects of acceptance. Taste was paramount. Participants would not consume more fluoridated salt than their current salt as that would result in unpleasant changes in food flavor and taste. While salt fluoridation is acceptable

  15. In vivo efficacy of tamarind (Tamarindus indica) fruit extract on experimental fluoride exposure in rats.

    Science.gov (United States)

    Dey, S; Swarup, D; Saxena, Anju; Dan, Ananya

    2011-12-01

    The study was undertaken to determine the efficacy of hydro-methanolic (1:1) extract of tamarind (Tamarindus indica L.) fruit pulp in removing body fluoride burden. Thirty rats were divided into five groups. Keeping no fluoride group as the control, rats of no treatment, low dose, middle dose and high dose groups received sodium fluoride orally at the rate of 200mg per kg body weight daily for 14 weeks. Rats of low dose, middle dose and high dose group simultaneously received tamarind fruit pulp extract at three doses, viz. 25 (low), 50 (medium) and 100mg (high) per kg body weight orally, respectively. Fluoride concentration in blood, urine and long bone of experimental rats was monitored to assess the efficacy of the extract. Mean serum fluoride concentration in fluoride exposed rats was 0.145 ± 0.009 and 0.783 ± 0.042 μg/ml on days 0 and 98. In comparison, fluoride concentrations in tamarind treated rats were 0.179 ± 0.021 and 0.633 ± 0.015; 0.179 ± 0.021 and 0.502 ± 0.025 and 0.176 ± 0.021 and 0.498 ± 0.030 μg/ml in low, medium and high dose groups, respectively on day 0 and day 98 of the experiment. There was a significant (p ≤ 0.01) increase in urinary fluoride excretion from day 28 onwards. The mean fluoride concentration in long bones of treated rats was significantly lower than the values recorded in fluoride exposed rats. These findings suggest that concomitant use of tamarind fruit pulp extract can reduce fluoride concentration in blood and bone and enhanced urinary excretion, indicating the ameliorative potential of fruits of tamarind in fluoride toxicity.

  16. Aluminum alloy

    Science.gov (United States)

    Blackburn, Linda B. (Inventor); Starke, Edgar A., Jr. (Inventor)

    1989-01-01

    This invention relates to aluminum alloys, particularly to aluminum-copper-lithium alloys containing at least about 0.1 percent by weight of indium as an essential component, which are suitable for applications in aircraft and aerospace vehicles. At least about 0.1 percent by weight of indium is added as an essential component to an alloy which precipitates a T1 phase (Al2CuLi). This addition enhances the nucleation of the precipitate T1 phase, producing a microstructure which provides excellent strength as indicated by Rockwell hardness values and confirmed by standard tensile tests.

  17. Effect of Fluoride, Casein Phosphopeptide–Amorphous Calcium Phosphate and Casein Phosphopeptide–Amorphous Calcium Phosphate Fluoride on Enamel Surface Microhardness After Microabrasion: An In Vitro Study

    Directory of Open Access Journals (Sweden)

    Ghazaleh Ahmadi Zenouz

    2016-03-01

    Full Text Available Objectives: This study aimed to assess the effect of applying casein phosphopeptide–amorphous calcium phosphate (CPP-ACP paste, casein phosphopeptide–amorphous calcium phosphate fluoride (CPP-ACPF paste and sodium fluoride gel on surface microhardness of enamel after microabrasion.Materials and Methods: Thirty freshly extracted human premolars were selected. All samples were subjected to hardness indentations made with the Vickers hardness machine and the average value was recorded as the initial surface microhardness. The specimens were then randomly divided into three groups (n=10 of CPP-ACPF, fluoride and CPP-ACP. The teeth were micro-abraded with Opalustre. Microhardness test was performed to assess the post-abrasion hardness. Three remineralization modalities were performed on samples of each group. The enamel surface microhardness measurements were performed. To compare the difference between groups, the rehardening and softening values were defined. One-way ANOVA and Tukey’s post hoc test at a significance level of 5% were used for statistical analysis.Results: The mean microhardness value (MMV had a significant decrease after microabrasion from baseline. The MMV had a significant increase after remineralization in all groups. The MMV of CPP-ACPF group was significantly more than that of fluoride group (P=0.027. The rehardening value of fluoride group was significantly more than that of other groups (P<0.001.Conclusion: All the remineralizing agents were effective for rehardening the enamel after microabrasion. The CPP-ACP and CPP-ACPF pastes are effective, but to a lesser extent than neutral sodium fluoride gel in remineralizing enamel surface. Incorporation of fluoride to CPP-ACP formulation does not provide any additional remineralizing potential.Keywords: Casein phosphopeptide-amorphous calcium phosphate nanocomplex; Enamel Microabrasion; Hardness; Sodium Fluoride

  18. Health Effects Associated with Water Fluoridation.

    Science.gov (United States)

    Richmond, Virginia L.

    1979-01-01

    Discussion is presented concerning fluoridation of water supplies. Correlation between fluoride in drinking water and improved dental health is reviewed. Relationship is expressed between fluoridation and reduced tooth decay. Use of fluoride in treating skeletal disorders is discussed. Author advocates fluoridating water supplies. (SA)

  19. Impacts of inorganic fluorides on terrestrial ecosystems: An ecological risk assessment case study

    Energy Technology Data Exchange (ETDEWEB)

    Kent, R.A.; Schneider, U.A.; Pawlisz, A.V. [Environment Canada, Hull, Quebec (Canada). Evaluation and Interpretation Branch

    1995-12-31

    In 1994, the national environmental assessment under the Canadian Environmental Protection Act concluded that concentrations of inorganic fluorides near industrial sources in Canada may cause long-term adverse effects in sensitive terrestrial plant and wildlife species. This case study examines the accumulation of inorganic fluorides in vegetation and subsequent effects on a sensitive herbivore species, the white tail deer (Odocoileus virginianus) on Cornwall Island, Ontario, near an aluminum smelting facility, Using environmental concentration data for air, water and food (vegetation), a Monte Carlo simulation was used to estimate the probability that multimedia exposure of inorganic fluorides exceeded known effects thresholds of skeletal and dental fluorosis in deer, and in turn quantify the magnitude of that risk. With daily intakes ranging from 2--324 {micro}g/deer/day, it was estimated that exposure to fluorides exceeds the daily intake threshold for fluorosis (55 {micro}g/deer/day) in 12% of the deer population. Seasonal differences in exposure and subsequent risk were noted. These results are also supported by additional field data on domestic cattle from the Cornwall Island area where effects (e.g., excessive teeth wear, delayed eruption of permanent teeth, osteosclerosis, osteonecrosis) have been reported and linked to high levels of fluorides in air, water, and forage. It is estimated that at least 10% of the deer from the Cornwall Island area may be subject to debilitating skeletal and dental fluorosis as a result of fluoride emissions from the adjacent aluminum smelter.

  20. Randomized Equivalence Trial of Intensive and Semiannual Applications of Fluoride Varnish in the Primary Dentition

    OpenAIRE

    Weinstein, P; Spiekerman, C.; Milgrom, P

    2009-01-01

    For children in the primary dentition with high caries prevalence the standard semiannual application of fluoride varnish may not be successful in preventing tooth decay. Oftentimes this population is mobile and does not receive consistent preventive care. This trial tested whether an intensive fluoride 5% sodium varnish regimen (three applications/2 weeks) applied annually has an equivalent effect on caries progression in the primary dentition compared to single applications applied semiannu...

  1. 氟化物联合五倍子水提取物对变形链球菌影响的体外研究%The Study of in Vitro Influence of Sodium Fluoride Combined with Gallnut Water Extract of Streptococcus ;Mutans

    Institute of Scientific and Technical Information of China (English)

    徐小娟; 刘英志; 陈碧莲; 林静俐

    2015-01-01

    Objective:To study the effects of combined application of fluoride and the gallnut water extract on the growth and acidogenic metabolism of Streptococcus mutans(S.mutans).Method:10 mL of sterile culture tube 120 were selected and divided into 12 groups,1 group was control group,and 11 groups were experimental group,each group of 10. The experimental group standard S. mutans were cultured in vitro in the TS medium which contained 5%sucrose and different concentration of NaF(0.01%,0.02%)and/or gallnut water extract(0.25,0.5,1 mg/mL),and the medium without neither NaF nor gallnut water extract act as control group. The optical density(OD)value of the medium and pH change before and after the culture was determined. Result:Compared with the control group,the experimental group S.mutans growth was obviously inhibited,and with the increase of amount of sodium fluoride and gallnut water extract concentration of culture,the number of S.mutans showed a concentration dependent decrease;with the increase of sodium fluoride and the culture medium of gallnut water extract concentration,pH changes of medium of gradually reduced,NaF combined with gallnut water extract showed no obvious synergistic effect. Conclusion:NaF and gallnut water extract could significantly inhibit the growth and acidogenic metabolism of S. mutans. No obvious synergistic effect was observed while the NaF combined with gallnut water extract.%目的:研究氟化物与五倍子水提取物联合应用对变形链球菌生长和代谢的影响。方法:取10 mL的无菌培养管120支,分为12组,对照组1组,实验组11组,每组各10支。对照组中含无菌去离子水,实验组中含有不同浓度氟化钠(0.01%、0.02%)、五倍子水提取物(0.25、0.5、1 mg/mL)及氟化钠与五倍子联合应用的培养基内培养变形链球菌标准菌株,检测培养前后两组培养基光密度值及pH的变化。结果:与对照组相比,各实验组变链菌的生长受到

  2. Comparative study of analgesic effect of the infrared low-intensity laser and 33% sodium fluoride paste in the treatment of dentinal hypersensitivity; Estudo comparativo do efeito analgesico do laser em baixa intensidade de emissao infravermelha e da pasta de fluoreto de sodio a 33% no tratamento da hipersensibilidade dentinaria

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Glen Anderson Maia de

    2003-07-01

    Different desensitizing agents have been used in the treatment of dentinal hypersensitivity, however, some presented treatments are still frustrating. The purpose of this study was to evaluate the analgesic effect of the low-intensity GaAlAs laser ({lambda}= 830 nm) in the treatment of dentinal hypersensitivity after mechanical and thermal stimuli, and compared it with the 33% sodium fluoride paste. Thirty two teeth with dentinal hypersensitivity were selected and randomly divided into two groups. For the laser group, each tooth was irradiated by a dose of 6 J/cm{sup 2} during two minutes and half on the buccal side. The paste group was treated with a NaF/kaolin/glycerin (33:33:33) paste by burnishing the sensitive surface during four minutes. The sensitivity degree was measured before the beginning of the experiment, 24 h, 48 h, 72 h, 120 h, 15 days and 30 days after the first application. The results indicate that the dentinal hypersensitivity significantly diminished for the paste group after dental explorer. Regarding to air-blast, no significant differences were observed between the groups. Both of them were effective in reducing pain of the dentine hypersensitive after 120 h. (author)

  3. Elevated fluoride products enhance remineralization of advanced enamel lesions.

    Science.gov (United States)

    ten Cate, J M; Buijs, M J; Miller, C Chaussain; Exterkate, R A M

    2008-10-01

    Caries prevention might benefit from the use of toothpastes containing over 1500 ppm F. With few clinical studies available, the aim of this pH-cycling study was to investigate the dose response between 0 and 5000 ppm F of de- and remineralization of advanced (> 150 microm) enamel lesions. Treatments included sodium and amine fluoride, and a fluoride-free control. Mineral uptake and loss were assessed from solution calcium changes and microradiographs. Treatments with 5000 ppm F both significantly enhanced remineralization and inhibited demineralization when compared with treatments with 1500 ppm F. Slight differences in favor of amine fluoride over sodium fluoride were observed. The ratio of de- over remineralization rates decreased from 13.8 to 2.1 in the range 0 to 5000 ppm F. As much as 71 (6)% of the remineralized mineral was calculated to be resistant to dissolution during subsequent demineralization periods. With 5000-ppm-F treatments, more demineralizing episodes per day (10 vs. 2 for placebo) would still be repaired by remineralization.

  4. Chromogenic and fluorogenic Schiff base chemosensor for nano scale level fluoride detection with logical interpretation

    Science.gov (United States)

    Ghosh, Pritam; Banerjee, Priyabrata

    2016-10-01

    Schiff base Organic Frameworks (SOFs) based chemosensor have been synthesized and utilized for recognization of biologically relevant fluoride anion. The chemosensor is selective for fluoride (F-) and exhibits reversible UV-Vis response with alternate addition of aluminum (Al3+). Interestingly a fluorescence 'turn on' response has been noticed with concomitant addition of fluoride. TICT, PTTS and restricted Cdbnd N isomerization has been taken into account in order to explain the florescence 'turn on' phenomenon. Significantly, the limit of fluoride detection is nano molar level (∼10 nM). The reversible UV-Vis phenomena have been used for designing AND-NAND-NOT-NOR-OR-XOR-XNOR based complex logic circuit to prepare potential feedstock as 'Lab-on a-Molecule'.

  5. Permeability of eroded enamel following application of different fluoride gels and CO2 laser.

    Science.gov (United States)

    Lepri, Taísa Penazzo; Colucci, Vivian; Turssi, Cecília Pedroso; Corona, Silmara Aparecida Milori

    2013-01-01

    This study evaluated the combined effect of fluoride compounds and CO(2) laser in controlling the permeability of eroded enamel. Bovine enamel slabs (3 × 2 mm) were cycled twice through an alternating erosion and remineralization regimen. Slabs were immersed in 20 ml of orange juice (pH 3.84) for 5 min under agitation, rinsed with deionized water, and stored in artificial saliva for 4 h to form erosive lesions. Specimens were then divided into four groups (n = 10), which were treated for 1 min with either a control or with one of the following gels: amine fluoride (AmF), titanium tetrafluoride (TiF(4)), or sodium fluoride (NaF). Half of the specimens were irradiated with a CO(2) laser (λ = 10.6 μm; 2.0 W). Specimens were cycled two more times through the aforementioned erosion-remineralization regimen and were subjected to permeability assessment. ANOVA demonstrated a significant interaction between fluoride and laser treatment (p = 0.0152). Tukey's test showed that when fluoride was applied alone, TiF(4) resulted in lower enamel permeability than that observed after application of the placebo gel. Intermediate permeability values were noted after NaF and AmF had been used. A significant reduction in enamel permeability was obtained when fluoride was combined with CO(2) laser treatment, with no difference between fluoride gels. Permeability of eroded enamel may be reduced by combining the application of fluoride gels with CO(2) laser irradiation.

  6. Geochemical factors controlling the occurrence of high fluoride groundwater in the Nagar Parkar area, Sindh, Pakistan.

    Science.gov (United States)

    Rafique, Tahir; Naseem, Shahid; Usmani, Tanzil Haider; Bashir, Erum; Khan, Farooque Ahmed; Bhanger, Muhammad Iqbal

    2009-11-15

    Fluoride concentrations in groundwater near Nagar Parkar in the Thar Desert of southeastern Pakistan range from 1.13 to 7.85 mg/l, and roughly 78% of the samples contain fluoride in concentrations that exceed the drinking water standard of 1.5mg/l set by WHO. The groundwater is alkaline (pH 7.1-8.4), brackish (TDS 449-15,933 mg/l), and classified as Na-Cl type water. This prevailing chemical character reflects the influence of saltwater intrusion, high evaporation rates, and ion exchange. Groundwater is also supersaturated with respect to calcite, which promotes the removal of Ca(2+) and HCO(3)(-) from solution. As a result, groundwater is generally undersaturated with respect to fluorite, the mineral that typically controls the upper limit of fluoride concentrations. This study examines a number of geochemical parameters in an effort to discover the controls on fluoride concentrations in groundwater. High fluoride concentrations are associated with high TDS, high pH, high Na concentrations, and high sodium absorption ratios (SAR). This suggests that elevated fluoride levels are the result of enhanced fluorite solubility due to Ca depletion and high ionic strength and the release of fluoride from colloid surfaces under high pH conditions. Contrary to what has been found in other studies, sample depth and water temperature do not appear to have a significant role in the distribution of fluoride within the groundwater.

  7. Sodium (Salt or Sodium Chloride)

    Science.gov (United States)

    ... Some food companies have already been working to reduce sodium in many of their products. Learn more and ... sodium with these printable and sharable infographics. The Salty Six – Common Foods that Add the Most Sodium ...

  8. EFFECT OF FLUORIDE ON KIDNEY OF ALBINO RABBIT-AN EXPERIMENTAL STUDY

    Directory of Open Access Journals (Sweden)

    Santosh K.

    2014-08-01

    Full Text Available BACKGROUND: Fluoride is present in environment in various forms and ingested by man from solid foods, drinks, drinking water and inhaled from the air. Out of these, fluoride is present in large quantities in dissolved state in many sources of drinking water producing toxicity in man. Fluoride, being excreted mainly through the kidneys, seems to damage it causing renal dysfunction. Kidneys are among the most sensitive body organs in their histopathological and functional responses to excessive amounts of fluoride. Trace elements are essential and beneficial to human being in minute concentrations. However, intake in large quantities produces adverse and toxic effects on our body. OBJECTIVE: The present study was designed to investigate the toxic effects (evaluated as histopathological changes of sodium fluoride on the kidney in albino rabbit. MATERIALS AND METHODS: Total 40 albino rabbits were used for this study, among them 8 rabbits were taken in the control group (Group A and16 rabbits each were taken in both group B and group C who were administered low and high dose of fluoride respectively. After 2 weeks interval, up to 16 weeks the histology of the kidney of each group of the rabbit was studied for histological analysis. RESULT: Histological changes in the kidneys of both Group B and Group C rabbits, following continuous daily exposure to sodium fluoride solutions in two different doses (0.5% solution for Group B and 3% solution for Group C for different durations of time were studied in detail and compared with those of the controls (Group A. CONCLUSION: It is concluded that Sodium Fluoride solution in high doses for prolonged period has a definite adverse effect on the renal parenchyma.

  9. Avaliação da superfície de braquetes de titânio após a aplicação de fluoreto de sódio Evaluation of titanium brackets surface after immersion in sodium fluoride

    Directory of Open Access Journals (Sweden)

    Luciane Macedo de Menezes

    2006-06-01

    the same described procedures. All brackets were evaluated by macroscopic (visual appearence and scanning microscopy (Philips, model XL 30, before and after the procedures. RESULTS: titanium brackets submitted to fluoride (NaF, groups B and C, presented discoloration (matte gray color when compared to group A. Stainless steel brackets showed no color alteration. CONCLUSION: titanium and stainless steel brackets showed no change in surface roughness or chemical components when immersed in sodium fluoride solution.

  10. An exposure and risk assessment for fluoride and trace metals in black tea

    Energy Technology Data Exchange (ETDEWEB)

    Sofuoglu, Sait C. [Izmir Institute of Technology, Department of Chemical Engineering and Environmental Research Center, Guelbahce, Urla 35430 Izmir (Turkey)], E-mail: cemilsofuoglu@iyte.edu.tr; Kavcar, Pinar [Izmir Institute of Technology, Department of Chemical Engineering and Environmental Research Center, Guelbahce, Urla 35430 Izmir (Turkey)], E-mail: pinarkavcar@iyte.edu.tr

    2008-10-30

    Exposure and associated health risks for fluoride and trace metals in black tea were estimated. Fifty participants were randomly recruited to supply samples from the tea that they drink, and self-administer a questionnaire that inquired about personal characteristics and daily tea intake. Analyzed trace metals included aluminum, arsenic, barium, cadmium, cobalt, chromium, copper, manganese, nickel, strontium, and zinc. Fluoride and four metals (Al, Cr, Mn, Ni) were detected in all samples while barium was detected only in one sample. The remaining metals were detected in >60% of the samples. Fluoride and aluminum levels in instant tea bag samples were greater than in loose tea samples (p < 0.05) while the differences in elemental concentrations of loose and pot bag tea samples were not significant. Median and 90th percentile daily tea intake rates were estimated as 0.35 and 1.1 l/day, respectively. Neither fluoride nor aluminum levels in black tea were found to associate with considerable risks of fluorosis and Alzheimer's disease, respectively. However, carcinogenic risk levels for arsenic were high; R > 1.0 x 10{sup -6} even at the median level. According to sensitivity analysis, daily tea intake was the most influencing variable to the risk except for arsenic for which the concentration distribution was of more importance.

  11. 49 CFR 173.163 - Hydrogen fluoride.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Hydrogen fluoride. 173.163 Section 173.163... Hydrogen fluoride. (a) Hydrogen fluoride (hydrofluoric acid, anhydrous) must be packaged as follows: (1) In... filling ratio of 0.84. (b) A cylinder removed from hydrogen fluoride service must be condemned...

  12. Fluoride in the drinking water of Pakistan and the possible risk of crippling fluorosis

    Directory of Open Access Journals (Sweden)

    M. A. Tahir

    2012-09-01

    Full Text Available To explore the possibility of fluoride toxicity, seven hundred and forty seven (747 water samples were collected from surface and ground water sources of sixteen major cities of Pakistan, adopting a uniform sampling design with distribution of samples as: Lahore (79, Kasur (46, Faisalabad (30, Khushab (50, Chakwal (51, Mianwali (30, Jhelum (53, Bahawalpur (60, Karachi (60, Mirpur Khas (55, Peshawar (38, Risalpur (35, Quetta (81, Ziarat (21, Loralai (21, Mastung (37. The comparison of analytical findings with WHO Guidelines of Drinking Water for Fluoride (i.e. 1.5 ppm has concluded that 16% of the monitored water sources have fluoride concentration beyond the permissible, safe limit of 1.5 mg l−1, falling in the concentration range of 1.6–25 mg l−1. The highest fluoride contamination (22% has been detected in the Balochistan province followed by 19% in Punjab province. Comparatively higher fluoride levels of >20% in groundwater sources such as hand pumps has supported the possibility of increased ground water contamination, as excessive fluoride concentrations are expected to come from calcium-poor aquifers and from areas where fluoride-bearing minerals are common or where cation exchange of sodium for calcium occurs. Field observations have also indicated the prevalence of fluoride-associated health implications in the study areas with excessive fluoride in water sources. The findings in this study have provided a bidirectional vision for epidemiological investigations as well as for mitigating the issues in the affected vicinities of fluoride-rich areas.

  13. Fluoride-induced chronic renal failure.

    Science.gov (United States)

    Lantz, O; Jouvin, M H; De Vernejoul, M C; Druet, P

    1987-08-01

    Renal fluoride toxicity in human beings is difficult to assess in the literature. Although experimental studies and research on methoxyflurane toxicity have shown frank renal damage, observations of renal insufficiency related to chronic fluoride exposure are scarce. We report a case of fluoride intoxication related to potomania of Vichy water, a highly mineralized water containing 8.5 mg/L of fluoride. Features of fluoride osteosclerosis were prominent and end-stage renal failure was present. The young age of the patient, the long duration of high fluoride intake, and the absence of other cause of renal insufficiency suggest a causal relationship between fluoride intoxication and renal failure.

  14. New observations on chronic intoxication by very small doses of sodium fluosilicate

    Energy Technology Data Exchange (ETDEWEB)

    Cristiani, H.; Chausse, P.

    1927-01-01

    It was determined that daily doses of approximately 0.1 of the lethal dose of sodium fluoride produced a fluoric cachexia in guinea pigs which caused the death of the animals in 2 or 3 months. Animals which were given 0.02 of the lethal dose of sodium fluoride were apparently in good health for a period of 10 months. However, after two or three years cachexia was likely to appear.

  15. Efficacy of xylitol and fluoride mouthrinses on salivary mutans streptococci

    Institute of Scientific and Technical Information of China (English)

    Sroisiri Thaweboon; Yuwadee Asvanund; Kesinee Charoenchaikorn

    2011-01-01

    To evaluate the level of salivary Mutans streptococci (MS) after rinsing with xylitol, fluoride, and a combination of xylitol and fluoride solutions, compared with distilled water. Methods: Eighty healthy 8-9 years old subjects with high level of MS (> 105 CFU/mL) were equally divided into 4 groups. Subjects rinsed their mouths for 1 min with 10 mL of 0.05% (w/v) sodium fluoride (NaF), 12.5% (w/v) xylitol or 0.05% (w/v) NaF + 12.5% (w/v) xylitol 3 times daily over 10 weeks. Distilled water rinsed group served as a control. Paraffin-stimulated whole saliva samples were collected at baseline, 5 weeks, and 10 weeks after rinsing to determine the level of salivary MS by culturing on Mitis Salivarius Bacitracin agar. The statistical significance was calculated by Kruskal Wallis, Mann Whitney U, and Wilcoxon signed-rank tests at a significant level ofP< 0.05. Results: Significant reductions in MS count were observed in subjects using 0.05% NaF+ 12.5% xylitol over other groups within 5 weeks and after 10 weeks and 12.5% xylitol alone after 10 weeks compared with baseline. Conclusions: The present study provides evidence for the inhibitory effect of xylitol, used in combination with fluoride, delivered in the form of mouthrinse, on salivary MS in the group of schoolchildren.

  16. Professionally applied fluoride gel in low-caries 10.5-year-olds.

    Science.gov (United States)

    Truin, G J; van 't Hof, M A

    2005-05-01

    The question has been raised whether low-caries children regularly using fluoride toothpaste will benefit from the professional application of additional fluoride gel. To investigate the caries-reducing effect of semi-annually-applied neutral 1% sodium fluoride gel, we carried out a double-blind randomized controlled clinical trial (n = 594) in a child population, initially aged 9.5-11.5 years, with baseline caries experience of D3MFS = 0 (decayed, missing, and filled tooth surfaces of permanent teeth). The mean number of tooth surfaces saved from caries development by fluoride gel application after 4 years was 0.2 D3MFS (SE = 0.17). The preventive fraction (PF) showed a mean relative effect of professionally applied fluoride gel of 18%. The cariostatic effect of the fluoride gel on pits and fissures would have been influenced by the sealant strategy in the study. Professionally applied fluoride gel showed no statistically significant effect on mean D3MFS score in low-caries 9.5- to 11.5-year-olds.

  17. Enhancement of Saharan groundwater quality by reducing its fluoride concentration using different materials

    KAUST Repository

    Ramdani, Amina

    2014-04-15

    According to the environmental protection regulations, fluoride concentration is considered as a substance of priority for assessment of drinking water quality to determine their impacts on the environment and public health. Saharan groundwater (Algeria) contains an excess of fluoride ions. Regular consumption of this water by the population of the region may cause endemic fluorosis. To solve this problem, we propose to treat this water by adsorption on different materials, such as activated alumina (AA), sodium clay (SC), and hydroxyapatite (HAP) in order to enhance its quality by reducing its fluoride concentration. The maximum adsorption is achieved with an adsorption capacity of the order of 0.9, 0.667, and 0.370 mg/g and with a percentage of 90, 83.4, and 73.95% for AA, HAP, and SC, respectively. Indeed, the acidity and alkalinity of the medium significantly affect the adsorption of fluoride ions. Results deduced from the curves of adsorption isotherms of fluoride ions showed that the retention is predictable from these isotherms in agreement with the Langmuir model. The low removal of fluoride ions was observed in presence of (Formula presented.), (Formula presented.), and (Formula presented.) ions. Finally, AA material proved to be the best adsorbent for fluoride ions removal. © 2014 © 2014 Balaban Desalination Publications. All rights reserved.

  18. Fluorination utilizing thermodynamically unstable fluorides and fluoride salts thereof

    Energy Technology Data Exchange (ETDEWEB)

    Bartlett, Neil (Orinda, CA); Whalen, J. Marc (Corning, NY); Chacon, Lisa (Corning, NY)

    2000-12-12

    A method for fluorinating a carbon compound or cationic carbon compound utilizes a fluorination agent selected from thermodynamically unstable nickel fluorides and salts thereof in liquid anhydrous hydrogen fluoride. The desired carbon compound or cationic organic compound to undergo fluorination is selected and reacted with the fluorination agent by contacting the selected organic or cationic organic compound and the chosen fluorination agent in a reaction vessel for a desired reaction time period at room temperature or less.

  19. Inert Anode Life in Low Temperature Reduction Process

    Energy Technology Data Exchange (ETDEWEB)

    Bradford, Donald R.

    2005-06-30

    The production of aluminum metal by low temperature electrolysis utilizing metal non-consumable anodes and ceramic cathodes was extensively investigated. Tests were performed with traditional sodium fluoride--aluminum fluoride composition electrolytes, potassium fluoride-- aluminum fluoride electrolytes, and potassium fluoride--sodium fluoride--aluminum fluoride electrolytes. All of the Essential First-Tier Requirements of the joint DOE-Aluminum Industry Inert Anode Road Map were achieved and those items yet to be resolved for commercialization of this technology were identified. Methods for the fabrication and welding of metal alloy anodes were developed and tested. The potential savings of energy and energy costs were determined and potential environmental benefits verified.

  20. The efficacy of an intraoral fluoride-releasing system in irradiated head and neck cancer patients: a preliminary study.

    Science.gov (United States)

    Meyerowitz, C; Watson, G E

    1998-09-01

    This study compared the anticaries effectiveness of an intraoral fluoride-releasing system, or IFRS, with a standard regimen of daily application of a 1.1 percent neutral sodium fluoride gel in custom trays. Caries protection in subjects in the IFRS group was comparable to that in subjects in the 1.1 percent neutral sodium fluoride group. The subjects all had head or neck cancer and had received radiation therapy, but no more recently than three months before taking part in the study. Overall, IFRS devices were well-tolerated and patient satisfaction was high. The IFRS appears to offer several advantages over the daily application of fluoride gels in custom trays.

  1. Sodium Oxybate

    Science.gov (United States)

    Sodium oxybate is used to prevent attacks of cataplexy (episodes of muscle weakness that begin suddenly and ... urge to sleep during daily activities, and cataplexy). Sodium oxybate is in a class of medications called ...

  2. Sodium Test

    Science.gov (United States)

    ... be limited. Home Visit Global Sites Search Help? Sodium Share this page: Was this page helpful? Also known as: Na Formal name: Sodium Related tests: Chloride , Bicarbonate , Potassium , Electrolytes , Osmolality , Basic ...

  3. Sodium Phosphate

    Science.gov (United States)

    Sodium phosphate is used in adults 18 years of age or older to empty the colon (large intestine, bowel) ... view of the walls of the colon. Sodium phosphate is in a class of medications called saline ...

  4. Efecto de la arginina 8%-carbonato de calcio y del fluoruro de sodio al 5% en la reducción de la hipersensibilidad dentinaria post terapia periodontal: ensayo clínico Effect of 8% arginine, calcium carbonate and 5% sodium fluoride on the reduction of the dentine hipersensitivity post periodontal therapy: clinical trial

    Directory of Open Access Journals (Sweden)

    M Márquez

    2011-04-01

    embargo, se logró una mayor reducción del dolor en aquellos pacientes que utilizaron la terapia de arginina al 8% y carbonato de calcio, con un 60% de los individuos sin dolor y con una mediana final de 0 en comparación al grupo con barniz de flúor al 5% y un dentrífico fluorado que mantuvieron en el 100% de los sujetos algún grado de dolor y presentando una mediana final en la escala VAS de 2.Aim: The aim of this clinical study was to evaluate and to compare the efficacy in reducing the dentine hypersensitivity of an 8% arginine, calcium carbonate, 1.450 ppm sodium monofluorophosphate dentifrice with topical application and twice-daily brushing, with a negative control toothpaste containing calcium carbonate and 1.450 ppm fluoride as MFP, after periodontal treatment (baseline and four weeks respectively. Methods: A four-week clinical study with 20 subjects with diagnosis of slight to moderate chronic periodontitis under mechanical periodontal treatment and presence of gingival recessions in incisors, canines or premolars, stratified based on baseline tooth sensitivity. Subjects brushed with either a 1.450 ppm fluoride dentifrice or a marketed 8% arginine calcium carbonate dentifrice twice daily for approximately one minute. At screening, baseline and weeks four, subjects' tooth sensitivity was determined through both evaporative (Schiff and Visual Analogue Scale [VAS]. The same examiner throughout the study performed subject assessments using each stimulus. Results: Both subject groups exhibited significant reductions from baseline to four weeks in dentine hypersensitivity. However, patients who received 8% arginine calcium carbonate therapy, exhibited a greater reduction, with a 60% of individuals lacking of pain and with a final median of 0 in comparison with the 5% fluoride varnish and fluoride toothpaste group in which a 100% of subjects felt some degree of pain, presenting a final medium VAS scale of 2.

  5. Effect of Enamel Caries Lesion Baseline Severity on Fluoride Dose-Response

    Directory of Open Access Journals (Sweden)

    Frank Lippert

    2017-01-01

    Full Text Available This study aimed to investigate the effect of enamel caries lesion baseline severity on fluoride dose-response under pH cycling conditions. Early caries lesions were created in human enamel specimens at four different severities (8, 16, 24, and 36 h. Lesions were allocated to treatment groups (0, 83, and 367 ppm fluoride as sodium fluoride based on Vickers surface microhardness (VHN and pH cycled for 5 d. The cycling model comprised 3 × 1 min fluoride treatments sandwiched between 2 × 60 min demineralization challenges with specimens stored in artificial saliva in between. VHN was measured again and changes versus lesion baseline were calculated (ΔVHN. Data were analyzed using two-way ANOVA (p<0.05. Increased demineralization times led to increased surface softening. The lesion severity×fluoride concentration interaction was significant (p<0.001. Fluoride dose-response was observed in all groups. Lesions initially demineralized for 16 and 8 h showed similar overall rehardening (ΔVHN and more than 24 and 36 h lesions, which were similar. The 8 h lesions showed the greatest fluoride response differential (367 versus 0 ppm F which diminished with increasing lesion baseline severity. The extent of rehardening as a result of the 0 ppm F treatment increased with increasing lesion baseline severity, whereas it decreased for the fluoride treatments. In conclusion, lesion baseline severity impacts the extent of the fluoride dose-response.

  6. FLUORIDE TOXICITY – A HARSH REALITY

    Directory of Open Access Journals (Sweden)

    Bandlapalli Pavani

    2011-04-01

    Full Text Available There are many incidents of fluoride toxicity whether it is acute or chronic. Fluoride toxicity is an environmental hazard which arises from the upper layers of geological crust and is dissolved in water. Prolonged drinking of such water causes chronic fluoride toxicity. Use of fluoride containing compounds for various purposes such as dental products, metal, glass, refrigerator and chemical industries act as a source of fluoride poisoning and increase the risk of toxicity. This review reflects the deleterious effects of fluorides on various organs in the physiological system.

  7. Chronic fluoride toxicity: dental fluorosis.

    Science.gov (United States)

    Denbesten, Pamela; Li, Wu

    2011-01-01

    Dental fluorosis occurs as a result of excess fluoride ingestion during tooth formation. Enamel fluorosis and primary dentin fluorosis can only occur when teeth are forming, and therefore fluoride exposure (as it relates to dental fluorosis) occurs during childhood. In the permanent dentition, this would begin with the lower incisors, which complete mineralization at approximately 2-3 years of age, and end after mineralization of the third molars. The white opaque appearance of fluorosed enamel is caused by a hypomineralized enamel subsurface. With more severe dental fluorosis, pitting and a loss of the enamel surface occurs, leading to secondary staining (appearing as a brown color). Many of the changes caused by fluoride are related to cell/matrix interactions as the teeth are forming. At the early maturation stage, the relative quantity of amelogenin protein is increased in fluorosed enamel in a dose-related manner. This appears to result from a delay in the removal of amelogenins as the enamel matures. In vitro, when fluoride is incorporated into the mineral, more protein binds to the forming mineral, and protein removal by proteinases is delayed. This suggests that altered protein/mineral interactions are in part responsible for retention of amelogenins and the resultant hypomineralization that occurs in fluorosed enamel. Fluoride also appears to enhance mineral precipitation in forming teeth, resulting in hypermineralized bands of enamel, which are then followed by hypomineralized bands. Enhanced mineral precipitation with local increases in matrix acidity may affect maturation stage ameloblast modulation, potentially explaining the dose-related decrease in cycles of ameloblast modulation from ruffle-ended to smooth-ended cells that occur with fluoride exposure in rodents. Specific cellular effects of fluoride have been implicated, but more research is needed to determine which of these changes are relevant to the formation of fluorosed teeth. As further

  8. Fluoride level in saliva after bonding orthodontic brackets with a fluoride containing adhesive

    NARCIS (Netherlands)

    Ogaard, B; Arends, J; Helseth, H; Dijkman, G; vanderKuijl, M

    1997-01-01

    The fluoride level in saliva is considered an important parameter in caries prevention. Elevation of the salivary fluoride level by a fluoride-releasing orthodontic bonding adhesive would most likely be beneficial in the prevention of enamel caries. In this study, the fluoride level in saliva was me

  9. Fluoridering af drikkevandet i Danmark?

    DEFF Research Database (Denmark)

    Arvin, Erik; Spliid, Henrik; Bruvo, M.;

    2010-01-01

    Første gang sammenhængen mellem caries (huller i tænderne) og fluoridindholdet i drikkevand blev diskuteret i vandværkskredse i Danmark var ved årsmødet i 1958. Her blev det oplyst, at fluorid i drikkevand beskytter mod caries, men man konstaterede også, at der nok ikke var stemning for fluorid......-tilsætning til drikkevandet (fluoridering). Siden da er emnet ikke taget op. Formålet med dette indlæg er at besvare spørgsmålene: 1. Er der behov for fluoridering af drikkevandet i Danmark? 2. Er der alternativer? Hvordan påvirker blødgøring af vand og andre vandbehandlingsmetoder dental caries hos børn og unge......? Som baggrund herfor vil vi redegøre for resultaterne af et netop afsluttet studium af sammenhængen mellem caries og drikkevandets sammensætning, specielt m.h.t. luoridindholdet og vandets calciumindhold (hårdhed). Undersøgelsen bekræfter, at fluorid i drikkevand i væsentlig grad beskytter mod caries...

  10. Studies of aluminum in rat brain

    Energy Technology Data Exchange (ETDEWEB)

    Lipman, J.J.; Brill, A.B.; Som, P.; Jones, K.W.; Colowick, S.; Cholewa, M.

    1985-01-01

    The effects of high aluminum concentrations in rat brains were studied using /sup 14/C autoradiography to measure the uptake of /sup 14/C 2-deoxy-D-glucose (/sup 14/C-2DG) and microbeam proton-induced x-ray emission (microPIXE) with a 20-..mu..m resolution to measure concentrations of magnesium, aluminum, potassium, and calcium. The aluminum was introduced intracisternally in the form of aluminum tartrate (Al-T) while control animals were given sodium tartrate (Na-T). The /sup 14/C was administered intravenously. The animals receiving Al-T developed seizure disorders and had pathological changes that included cerebral cortical atrophy. The results showed that there was a decreased uptake of /sup 14/C-2DG in cortical regions in which increased aluminum levels were measured, i.e., there is a correlation between the aluminum in the rat brain and decreased brain glucose metabolism. A minimum detection limit of about 16 ppM (mass fraction) or 3 x 10/sup 9/ Al atoms was obtained for Al under the conditions employed. 14 refs., 4 figs., 1 tab.

  11. High-fluoride groundwater.

    Science.gov (United States)

    Rao, N Subba

    2011-05-01

    Fluoride (F(-)) is essential for normal bone growth, but its higher concentration in the drinking water poses great health problems and fluorosis is common in many parts of India. The present paper deals with the aim of establishment of facts of the chemical characteristics responsible for the higher concentration of F(-) in the groundwater, after understanding the chemical behavior of F(-) in relation to pH, total alkalinity (TA), total hardness (TH), carbonate hardness (CH), non-carbonate hardness (NCH), and excess alkalinity (EA) in the groundwater observed from the known areas of endemic fluorosis zones of Andhra Pradesh that have abundant sources of F(-)-bearing minerals of the Precambrians. The chemical data of the groundwater shows that the pH increases with increase F(-); the concentration of TH is more than the concentration of TA at low F(-) groundwater, the resulting water is represented by NCH; the TH has less concentration compared to TA at high F(-) groundwater, causing the water that is characterized by EA; and the water of both low and high concentrations of F(-) has CH. As a result, the F(-) has a positive relation with pH and TA, and a negative relation with TH. The operating mechanism derived from these observations is that the F(-) is released from the source into the groundwater by geochemical reactions and that the groundwater in its flowpath is subjected to evapotranspiration due to the influence of dry climate, which accelerates a precipitation of CaCO(3) and a reduction of TH, and thereby a dissolution of F(-). Furthermore, the EA in the water activates the alkalinity in the areas of alkaline soils, leading to enrichment of F(-). Therefore, the alkaline condition, with high pH and EA, and low TH, is a more conducive environment for the higher concentration of F(-) in the groundwater.

  12. Microcratering in Polyvinylidene Fluoride

    Science.gov (United States)

    Shu, Anthony John

    Dust is defined as macroparticles as small as a few molecules up to several micrometers in diameter. In the context of space exploration, it was originally seen only as a technical obstacle to applications; dust can damage instrument surfaces, coat mating surfaces preventing proper seals, and impair or obstruct measurements. Because of the ubiquity of dust in the solar system and its role in the origin of planets and other bodies, the study of dust and related phenomena has evolved to a scientific subdiscipline which can provide us insight into the origins and evolution of our solar system. In order to facilitate this, a hypervelocity dust accelerator has been built at the University of Colorado at Boulder and is being used to probe impact phenomena, dust mitigation techniques, dust detection techniques, and more. One such dust detector is a Polyvinylidene Fluoride (PVDF) dust detector. The PVDF dust detector is very lightweight and consumes little power. Due to these properties, PVDF detectors can potentially be used on any spacecraft to gain information on the local dust environment. It is not fully understood how this PVDF dust detector signal is generated, so at present can only be used as a dust counter. In this thesis I discuss the importance of the study of dust phenomena, describe the accelerator experiment, and describe a study conducted to determine the underlying physical principles of PVDF dust detectors. This included measuring crater size scaling laws, measuring the detailed shape of craters, and applying this data to simulations of the signals being generated by PVDF detectors.

  13. Molten fluorides for nuclear applications

    Directory of Open Access Journals (Sweden)

    Sylvie. Delpech

    2010-12-01

    Full Text Available The importance of pyrochemistry is being increasingly acknowledged and becomes unavoidable in the nuclear field. Molten salts may be used for fuel processing and spent fuel recycling, for heat transfer, as a homogeneous fuel and as a breeder material in fusion systems. Fluorides that are stable at high temperature and under high neutron flux are especially promising. Analysis of several field cases reveals that corrosion in molten fluorides is essentially due to the oxidation of metals by uranium fluoride and/or oxidizing impurities. The thermodynamics of this process are discussed with an emphasis on understanding the mass transfer in the systems, selecting appropriate metallic materials and designing effective purification methods.

  14. Fluoride: its role in dentistry

    Directory of Open Access Journals (Sweden)

    Livia Maria Andaló Tenuta

    2010-01-01

    Full Text Available In spite of decades of research on fluoride and the recognition of its role as the cornerstone of dental caries reduction in the last fifty years, questions still arise on its use at community, self-applied and professional application levels. Which method of fluoride delivery should be used? How and when should it be used? How can its benefits be maximized and still reduce the risks associated with its use? These are only some of the challenging questions facing us daily. The aim of this paper is to present scientific background to understand the importance of each method of fluoride use considering the current caries epidemiological scenario, and to discuss how individual or combined methods can be used based on the best evidence available.

  15. Sodium and Food Sources

    Science.gov (United States)

    ... Sources Top 10 Sources of Sodium How to Reduce Sodium Sodium Reduction Resources for Everyone Sodium Reduction Fact ... in processed food [PDF-867K] and how to reduce sodium. Sodium Reduction Is Challenging Types of food matter: ...

  16. Sodium in diet

    Science.gov (United States)

    Diet - sodium (salt); Hyponatremia - sodium in diet; Hypernatremia - sodium in diet; Heart failure - sodium in diet ... The body uses sodium to control blood pressure and blood volume. Your body also needs sodium for your muscles and nerves to work ...

  17. The Effect of Fluoride in Osteoporosis.

    Science.gov (United States)

    Hedlund, L. R.; Gallagher, J. C.

    1987-01-01

    This article discusses the effect of fluoride on bone tissue and the possible role of fluoride in the treatment of osteoporosis. At present, fluoride treatment should be restricted to clinical trials until its risks and benefits have been further evaluated. (Author/MT)

  18. Fluoride in African groundwater: Occurrence and mitigation

    NARCIS (Netherlands)

    Vasak, S.; Griffioen, J.; Feenstra, L.

    2010-01-01

    Fluoride in groundwater has both natural and anthropogenic sources. Fluoride bearing minerals, volcanic gases and various industrial and agricultural activities can contribute to high concentrations. High intake of fluoride from drinking water is the main cause of fluorosis and may lead to many othe

  19. Phase Transitions and Ferroelectricity in Sodium Antimony Fluoride

    Science.gov (United States)

    Murata, C. Rene; Raveane, William; Teong Tan, Yu; Christie, R. James; Aguirre, Michael; Photinos, Panos; Abrahams, Sidney C.

    2001-03-01

    The predicted ferroelectric property of NaSb_3F_10 has been confirmed experimentally, with a reproducible dielectric hysteresis loop that forms at room temperature under the application of 0.3 MV m-1 a.c. NaSb_3F_10 undergoes a calorimetric transition at a mean Tc » 457 K with entropy change 5.7 J mol-1 K-1, close to R ln 2. Melting is at 515 K with decomposition starting above 600 K. The phase transition exhibits a wide thermal hysteresis, indicative of a weak first order transition. The dielectric permittivity at 100 Hz increases steadily above 325 K by more than an order of magnitude, undergoing a major inflection at Tc » 432 K that continues to increase until melting. The 100 Hz dielectric loss at room temperature also increases an order of magnitude before undergoing an inflection at 431 K, then rises steadily until melting. A strong anomaly in electrical conductivity is observed at T_c. The pyroelectric coefficient of ceramic NaSb_3F_10 is 20 μC m-2 K-1 at 298 K.

  20. Hidden Sodium

    Centers for Disease Control (CDC) Podcasts

    2013-03-04

    In this podcast, learn about reducing sodium intake by knowing what to eat and the main sources of sodium in the diet. It's important for a healthy lifestyle.  Created: 3/4/2013 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 3/4/2013.

  1. Dietary sodium

    DEFF Research Database (Denmark)

    Graudal, Niels

    2015-01-01

    The 2013 Institute of Medicine (IOM) report "Sodium Intake in Populations: Assessment of Evidence" did not support the current recommendations of the IOM and the American Heart Association (AHA) to reduce daily dietary sodium intake to below 2,300 mg. The report concluded that the population......-based health outcome evidence was not sufficient to define a safe upper intake level for sodium. Recent studies have extended this conclusion to show that a sodium intake below 2,300 mg/day is associated with increased mortality. In spite of this increasing body of evidence, the AHA, Centers for Disease...... Control (CDC), other public health advisory bodies, and major medical journals have continued to support the current policy of reducing dietary sodium....

  2. ALUMINUM BOX BUNDLING PRESS

    Directory of Open Access Journals (Sweden)

    Iosif DUMITRESCU

    2015-05-01

    Full Text Available In municipal solid waste, aluminum is the main nonferrous metal, approximately 80- 85% of the total nonferrous metals. The income per ton gained from aluminum recuperation is 20 times higher than from glass, steel boxes or paper recuperation. The object of this paper is the design of a 300 kN press for aluminum box bundling.

  3. Phytotoxicity of Sodium Fluoride and Uptake of Fluoride in Willow Trees

    DEFF Research Database (Denmark)

    Clausen, Lauge Peter Westergaard; Gosewinkel Karlson, Ulrich; Trapp, Stefan

    2015-01-01

    The willow tree (Salix viminalis) toxicity test and a cress seed germination test (Lepidium sativum) were used to determine uptake and phytotoxicity of NaF. Concentrations in hydroponic solutions were 0-1000 mg F/L and 0-400 mg F/L in the preliminary and definitive test. A third test was done...

  4. Preparation and characterization of aluminum stearate

    Directory of Open Access Journals (Sweden)

    Lončar Eva S.

    2003-01-01

    Full Text Available Preparation of aluminum stearate by the precipitation method was examined under various conditions of stearic acid saponification with sodium hydroxide. It was proved that the most favorable ratio of acid/alkali was 1:1.5 and that the obtained soap was very similar to the commercial product. Endothermic effects determined by differential scanning calorimetry and also the other parameters showed that the soaps consisted mono-, di-, tristearates and non-reacted substances, where distearate was the dominant form.

  5. Effects of fluoride air pollution on citrus orchards in the Kanbara district, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Y.

    1967-01-01

    Since the construction of the largest Japanese aluminum plant in 1942 in Kanbara, the effects of fluorides have been evident in the surrounding agricultural and silk industries. Kanbara is a principal citrus growing area, and for several years, the orange crop has been severely affected. During the rainy spring and summer, air pollution from fluoride increases, causing leaf and fruit drop as well as poor tree growth. Trees yield poorly, and the quality of the fruit which is produced is inferior. Spraying with OED or lime-sulfur solutions had no effect on these damages; the use of wind-breaking hedges to shut out the fluoride-laden air was slightly beneficial. The resistance of 251 wild and cultivated plants around the factory was investigated. Plants of the Equisetaeae, Orchidaceae, Iridaceae, Liliaceae, Araceae, Rosaceae, and Rutaceae families are sensitive to the effects of fluorides. Plants belonging to the Composita, Apiaceae, Lamiaceae and Teaceae families are not. Of the citrus plants, sweet orange (Citrus sinensis Osbec) is sensitive to fluorides, as are Matsudaidai, Iyo and Satsuma orange trees. According to a leaf analysis performed in September 1966, affected and non-affected leaves of Satsuma orange trees from 30 orchards up to 20 km distant from the factory, contained 135-378 p.p.m. fluoride in the affected area, while leaves from non-affected areas contained 9-82 p.p.m. Recommended indicator plants for fluoride air pollution are Equisetum arvense L., Sasa species, Reymoutria japonica Hout, Colocasia antiquorum Schott, Prunus mume Sieb, Irida species, and Gladiolus gandavensis Hout.

  6. Special Report: Fluoridation of Water.

    Science.gov (United States)

    Hileman, Bette

    1988-01-01

    Reviews the controversy regarding water fluoridation in the United States during the last 50 years. Discusses the current status; benefits; and health risks including skeletal fluorosis, kidney disease, hypersensitivity, mutagenic effects, birth defects, and cancer. Presents statistics and anecdotal accounts. (CW)

  7. Molten Triazolium Chloride Systems as New Aluminum Battery Electrolytes

    DEFF Research Database (Denmark)

    Vestergaard, B.; Bjerrum, Niels; Petrushina, Irina;

    1993-01-01

    The possibility of using molten mixtures of 1,4-dimethyl-1,2,4-triazolium chloride (DMTC) and aluminum chloride (AlCl3) as secondary battery electrolytes was studied, in some cases extended by the copresence of sodium chloride. DMTC-AlCl, mixtures demonstrated high specific conductivity in a wide...... of milliamperes per square centimeter) was observed at 0.344 V on the acidic sodium tetrachloroaluminate background, involving a free triazolium radical mechanism. Molten DMTC-AlCl3 electrolytes are acceptable for battery performance and both the aluminum anode and the triazolium electrolyte can be used as active...

  8. Fissure seal or fluoride varnish?

    Science.gov (United States)

    Deery, Christopher

    2016-09-01

    Data sourcesCochrane Oral Health Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Embase, the US National Institutes of Health Trials Register and the World Health Organization (WHO) Clinical Trials Registry PlatformStudy selectionRandomised controlled trials (RCTs) with at least 12 months follow-up, in which fissure sealants, or fissure sealants together with fluoride varnishes, were compared with fluoride varnishes alone for preventing caries in occlusal surfaces of permanent teeth of children and adolescents.Data extraction and synthesisTwo reviewers independently screened search results, extracted data and assessed risk of bias of included studies. Studies were grouped and analysed on the basis of sealant material type (resin-based sealant and glass ionomer-based sealant, glass ionomer and resin-modified glass ionomer) and different follow-up periods. Odds ratio were calculated for caries or no caries on occlusal surfaces of permanent molar teeth. Mean differences were calculated for continuous outcomes and data. Evidence quality was assessed using GRADE (Grades of Recommendation, Assessment, Development and Evaluation) methods.ResultsEight RCTs involving a total of 1747 children aged five to ten years of age were included. Three trials compared resin-based fissure sealant versus fluoride varnish. Results from two studies (358 children) after two years were combined. Sealants prevented more caries, pooled odds ratio (OR) = 0.69 (95%CI; 0.50 to 0.94). One trial with follow-up at four and nine years found that the caries-preventive benefit for sealants was maintained, with 26% of sealed teeth and 55.8% of varnished teeth having developed caries at nine years. Evidence for glass-ionomer sealants was of low quality. One split-mouth trial analysing 92 children at two-year follow-up found a significant difference in favour of resin-based fissure sealant together with fluoride varnish compared with fluoride varnish only (OR

  9. Global affordability of fluoride toothpaste

    Directory of Open Access Journals (Sweden)

    Holmgren Christopher J

    2008-06-01

    Full Text Available Abstract Objective Dental caries remains the most common disease worldwide and the use of fluoride toothpaste is a most effective preventive public health measure to prevent it. Changes in diets following globalization contribute to the development of dental caries in emerging economies. The aim of this paper is to compare the cost and relative affordability of fluoride toothpaste in high-, middle- and low-income countries. The hypothesis is that fluoride toothpaste is not equally affordable in high-, middle- and low-income countries. Methods Data on consumer prices of fluoride toothpastes were obtained from a self-completion questionnaire from 48 countries. The cost of fluoride toothpaste in high-, middle- and low-income countries was compared and related to annual household expenditure as well as to days of work needed to purchase the average annual usage of toothpaste per head. Results The general trend seems to be that the proportion of household expenditure required to purchase the annual dosage of toothpaste increases as the country's per capita household expenditure decreases. While in the UK for the poorest 30% of the population only 0.037 days of household expenditure is needed to purchase the annual average dosage (182.5 g of the lowest cost toothpaste, 10.75 days are needed in Kenya. The proportion of annual household expenditure ranged from 0.02% in the UK to 4% in Zambia to buy the annual average amount of lowest cost toothpaste per head. Conclusion Significant inequalities in the affordability of this essential preventive care product indicate the necessity for action to make it more affordable. Various measures to improve affordability based on experiences from essential pharmaceuticals are proposed.

  10. Toxicidade e acúmulo de flúor em hortaliças nas adjacências de uma fábrica de alumínio Toxicity and fluoride accumulation in herbs grown in the vicinity of an aluminum plant

    Directory of Open Access Journals (Sweden)

    Bruno Francisco Sant'Anna-Santos

    2010-12-01

    Full Text Available Com o objetivo de avaliar o potencial de acumulação de flúor e o percentual deste elemento removido pela lavagem, quatro espécies de hortaliças foram expostas em área poluída. Spondias dulcis foi utilizada como bioindicadora de reação e apresentou sintomas típicos em resposta ao poluente. Somente a salsa apresentou sintomas. Apesar de aparentemente sadias, as folhas das outras espécies utilizadas para estudos microscópicos, exceto da cebolinha, evidenciaram alterações na superfície, principalmente associados aos estômatos. Houve redução na espessura do limbo, mais acentuada no manjericão e na cebolinha, havendo formação de tecido de cicatrização na couve e condensação do conteúdo das células epidérmicas na salsa. As folhas subuladas e eretas da cebolinha favoreceram o menor acúmulo do poluente; já na salsa, as folhas laminares, recortadas e paralelas ao solo contribuíram para a maior retenção. A lavagem das folhas removeu 34,1 e 73,9% do flúor na cebolinha e na salsa, respectivamente, indicando que a maior parte do poluente encontrava-se internamente na cebolinha e externamente na salsa. O cultivo destas hortaliças em áreas poluídas por flúor é inadequado, pois os teores do poluente estão acima do recomendado para o consumo, mesmo após a lavagem das folhas.To assess fluoride accumulation potential and the percentage of fluoride removed by washing, four herb species were exposed to a polluted area. Spondias dulcis was used as a responsive bioindicator and showed typical fluoride response symptoms. Symptoms were observed only in parsley. Although apparently healthy, the leaves of the remaining herbs, except for chives, showed surface damage associated mainly with stomata when observed under the microscope. A reduction in leaf thickness was also observed, most prominently in basil and chives. Scar tissue was observed in kale, and a retraction of the protoplast of the epidermal cells was observed in parsley

  11. Sodium - blood

    Science.gov (United States)

    ... gland problems such as Cushing syndrome or hyperaldosteronism Diabetes insipidus (type of diabetes in which kidneys are not able to conserve water) Too much salt or sodium bicarbonate in the diet Use of certain medicines, including corticosteroids, laxatives, lithium, ...

  12. Prevalence of certain inorganic constituents in groundwater samples of Erode district, Tamilnadu, India, with special emphasis on fluoride, fluorosis and its remedial measures.

    Science.gov (United States)

    Karthikeyan, K; Nanthakumar, K; Velmurugan, P; Tamilarasi, S; Lakshmanaperumalsamy, P

    2010-01-01

    A total of 60 drinking water samples collected from Erode district, Tamilnadu, India were analysed for fluoride contamination, besides water quality parameters such as pH, electrical conductivity, total dissolved solids, total alkalinity, total hardness, fluoride, bicarbonates, calcium, magnesium, nitrate, sulphate, phosphate, sodium and potassium. The results obtained were found to exceed the permissible limits. The concentration of fluoride in the water samples ranged between 0.5 and 8.2 mg/l and revealed that 80% of the water samples contain fluoride above the maximum permissible limit. Similarly, the concentrations of nitrate, hardness, calcium and magnesium in some samples were also more than the permissible level. Pearson's correlation coefficient among the parameters showed a positive correlation of fluoride with total hardness and calcium. It is inferred from the study that these water sources can be used for potable purpose only after prior treatment.

  13. Fluoride retention in saliva and in dental biofilm after different home-use fluoride treatments.

    Science.gov (United States)

    Souza, Daniela Correia Cavalcante; Maltz, Marisa; Hashizume, Lina Naomi

    2014-01-01

    This single-blind, randomized, crossover study aimed at assessing the long-term fluoride concentrations in saliva and in dental biofilm after different home-use fluoride treatments. The study volunteers (n = 38) were residents of an area with fluoridated drinking water. They were administered four treatments, each of which lasted for one week: twice-daily placebo dentifrice, twice-daily fluoride dentifrice, twice-daily fluoride dentifrice and once-daily fluoride mouthrinse, and thrice-daily fluoride dentifrice. At the end of each treatment period, samples of unstimulated saliva and dental biofilm were collected 8 h after the last oral hygiene procedure. Fluoride concentrations in saliva and dental biofilm were analyzed using a specific electrode. The fluoride concentrations in saliva and dental biofilm 8 h after the last use of fluoride products did not differ among treatments. The results of this study suggest that treatments with home-use fluoride products have no long-term effect on fluoride concentrations in saliva and in dental biofilm of residents of an area with a fluoridated water supply.

  14. Final Technical Report Microwave Assisted Electrolyte Cell for Primary Aluminum Production

    Energy Technology Data Exchange (ETDEWEB)

    Xiaodi Huang; J.Y. Hwang

    2007-04-18

    This research addresses the high priority research need for developing inert anode and wetted cathode technology, as defined in the Aluminum Industry Technology Roadmap and Inert Anode Roadmap, with the performance targets: a) significantly reducing the energy intensity of aluminum production, b) ultimately eliminating anode-related CO2 emissions, and c) reducing aluminum production costs. This research intended to develop a new electrometallurgical extraction technology by introducing microwave irradiation into the current electrolytic cells for primary aluminum production. This technology aimed at accelerating the alumina electrolysis reduction rate and lowering the aluminum production temperature, coupled with the uses of nickel based superalloy inert anode, nickel based superalloy wetted cathode, and modified salt electrolyte. Michigan Technological University, collaborating with Cober Electronic and Century Aluminum, conducted bench-scale research for evaluation of this technology. This research included three sub-topics: a) fluoride microwave absorption; b) microwave assisted electrolytic cell design and fabrication; and c) aluminum electrowinning tests using the microwave assisted electrolytic cell. This research concludes that the typically used fluoride compound for aluminum electrowinning is not a good microwave absorbing material at room temperature. However, it becomes an excellent microwave absorbing material above 550°C. The electrowinning tests did not show benefit to introduce microwave irradiation into the electrolytic cell. The experiments revealed that the nickel-based superalloy is not suitable for use as a cathode material; although it wets with molten aluminum, it causes severe reaction with molten aluminum. In the anode experiments, the chosen superalloy did not meet corrosion resistance requirements. A nicked based alloy without iron content could be further investigated.

  15. Comparison of Antibacterial Effect of Fluoride and Chlorhexidine on Two Cariogenic Bacteria: An in Vitro Study

    Directory of Open Access Journals (Sweden)

    Poureslami HR

    2014-09-01

    Full Text Available Statement of problem: Dental plaque is the main source for dental caries and there is no proper vaccine that can affect dental plaques. Objectives: Daily use of an efficient anti-plaque product can be very beneficial in plaque control and, thus, prevention of caries. This study aims to evaluate the antibacterial effects of four products of Chlorhexidine and Fluoride on two types of cariogenic bacteria. Materials and Methods: In this in vitro study, the antibacterial effect of Chlorhexidine and Fluoride (gel and solution against Streptococci Sanguis and Sobrinus was evaluated. Chlorhexidine gluconate 1% gel (Corosodyl, France, Chlorhexidine gluconate 2% solution (Consepsis, Ultradent, US, Sodium fluoride 0.2% solution (Oral-B, US and Acidulated Phosphate Fluoride 1.23% gel ( Denti-Care, Canada were used. The disc diffusion method was used for testing bacterial sensitivity. The data were analyzed using paired t-test and Chi-square test. Results: In comparison with the negative control, each of the four gels and solutions showed antibacterial effects but the effects were not statistically significant for fluoride solution (P=0.217. For S. Sobrinus, the mean diameter of inhibition zone around the discs coated with fluoride gel (F g, fluoride solution (F s, Chlorhexidine gel (CHX g and Chlorhexidine solution (CHX s were 19, 9, 21.5 and 27.5mm, respectively. For S. Sanguis, the mean diameter of inhibition zone around the discs coated with F g, F s, CHX g and CHX s were 17, 11, 17 and 25mm, respectively. CHX s had the most effect on both bacteria and F s had the least. CHX g and F g were less effective than CHX s, respectively. Conclusion: The results demonstrated that 2% CHX s and 1.23% F g can be effective on inhibition of the growth of some of cariogenic bacteria. Therefore, these agents can be used in the prevention of Early Childhood Caries.

  16. Aspects of aluminum toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Hewitt, C.D.; Savory, J.; Wills, M.R. (Univ. of Virginia Health Sciences Center, Charlottesville (USA))

    1990-06-01

    Aluminum is the most abundant metal in the earth's crust. The widespread occurrence of aluminum, both in the environment and in foodstuffs, makes it virtually impossible for man to avoid exposure to this metal ion. Attention was first drawn to the potential role of aluminum as a toxic metal over 50 years ago, but was dismissed as a toxic agent as recently as 15 years ago. The accumulation of aluminum, in some patients with chronic renal failure, is associated with the development of toxic phenomena; dialysis encephalopathy, osteomalacic dialysis osteodystrophy, and an anemia. Aluminum accumulation also occurs in patients who are not on dialysis, predominantly infants and children with immature or impaired renal function. Aluminum has also been implicated as a toxic agent in the etiology of Alzheimer's disease, Guamiam amyotrophic lateral sclerosis, and parkinsonism-dementia. 119 references.

  17. Geochemistry of fluoride in the Black Creek aquifer system of Horry and Georgetown Counties, South Carolina--and its physiological implications

    Science.gov (United States)

    Zack, Allen L.

    1980-01-01

    High concentrations of fluoride in ground-water supplies in certain areas of Horry and Georgetown Counties, S.C., have been the cause of dental fluorosis (tooth mottling) among persons who have lived in these areas and have ingested the water as children. Geochemical evidence and laboratory experiments demonstrate that fluorapatite in the form of fossil shark teeth is the source of fluoride, and that the fluoride ions are liberated to the ground-water system through anion exchange, rather than by dissolution. Calcite-cemented quartz sand in the upper third of the Black Creek Formation of Late Cretaceous age contains the fossil shark teeth. As ground water progresses downdip, the calcite matrix dissolves and hydrolyzes, releasing bicarbonate, hydroxyl, and calcium ions. The calcium ions are immediately exchanged for sodium ions adsorbed on sodium-rich clays, and the bicarbonate ions accumulate. As the shark teeth are exposed, the hydroxyl ions in solution exchange with fluoride ions on fluorapatite surfaces. Experiments using fossil shark teeth show that sodium chloride in solution inhibits the rate of exchange of fluoride ions from tooth surfaces for hydroxyl ions in solution. The amount of fluoride removed from water and exchanged for hydroxyl ions in the presence of pure hydroxylapatite (hog teeth) was greater in saline water than in freshwater.

  18. Effect of strong acids on red mud structural and fluoride adsorption properties.

    Science.gov (United States)

    Liang, Wentao; Couperthwaite, Sara J; Kaur, Gurkiran; Yan, Cheng; Johnstone, Dean W; Millar, Graeme J

    2014-06-01

    The removal of fluoride using red mud has been improved by acidifying red mud with hydrochloric, nitric and sulphuric acid. The acidification of red mud causes sodalite and cancrinite phases to dissociate, confirmed by the release of sodium and aluminium into solution as well as the disappearance of sodalite bands and peaks in infrared and X-ray diffraction data. The dissolution of these mineral phases increases the amount of available iron and aluminium oxide/hydroxide sites that are accessible for the adsorption of fluoride. However, concentrated acids have a negative effect on adsorption due to the dissolution of these iron and aluminium oxide/hydroxide sites. The removal of fluoride is dependent on the charge of iron and aluminium oxide/hydroxides on the surface of red mud. Acidifying red mud with hydrochloric, nitric and sulphuric acid resulted in surface sites of the form ≡SOH2(+) and ≡SOH. Optimum removal is obtained when the majority of surface sites are in the form ≡SOH2(+) as the substitution of a fluoride ion does not cause a significant increase in pH. This investigation shows the importance of having a low and consistent pH for the removal of fluoride from aqueous solutions using red mud.

  19. Determination of Fluoride in Various Samples and Some Infusions Using a Fluoride Selective Electrode

    OpenAIRE

    TOKALIOĞLU, Şerife; Kartal, Şenol; ŞAHİN, Uğur

    2004-01-01

    The determination of fluoride in some environmental samples was performed using a fluoride ion-selective electrode. Fluoride concentrations were determined in drinking waters (from different provinces, districts and villages in Turkey), fruit juices, bottled water samples, toothpastes and tooth powders, liquors of Turkish coffee, coffee, linden, rose hip, and various brand tea infusions, and dust samples collected from the Erciyes University campus car park. The average fluoride conc...

  20. Using the pollen viability and morphology for fluoride pollution biomonitoring.

    Science.gov (United States)

    Malayeri, Behrooz Eshghi; Noori, Mitra; Jafari, Mehrana

    2012-06-01

    The methods using plants for biomonitoring of air and soil quality are simple, cheap, and fast and can supplement the classical physicochemical methods. In this study, biological pollen characterization of some collected legume species from an aluminum smelter area in Iran (IRALCO) was carried out to determine the actual value of pollen as a bioindicator of the effects of soil and atmospheric pollution. Young buds and flowers of six legumes (Cercis siliquastrum L., Medicago sativa L., Robinia pseudoacacia L., Melilotus officinalis (L.) lam, Trifolium repens L., and Sophora alopecuroides L.) in polluted and control plants were removed and compared. Studies of light and electron microscopic preparation showed some abnormalities during pollen development in affect of fluoride pollution. The viability of pollen grains estimated by staining with acetocarmine shows sharp differences in smearing advanced pollen grains from abnormal ones. Except M. officinalis, the pollen grains of C. siliquastrum, M. sativa, R. pseudoacacia, T. repens, and S. alopecuroides in polluted areas showed light, partial, or no staining with acetocarmine, whereas almost all of the control ones clearly stained. Observation of the pollen grains by light microscopy and scanning electron microscopy showed the significant effect of fluoride on shapes and sizes of pollen grains. The stimulation and inhibition of these pollen characteristics depend on the pollen species as well as on the pollutant and its concentration. Therefore, pollen grains provide essential information on biological impact of pollutants and they are good candidates for biomonitoring the atmospheric and edaphic pollutions.

  1. Aluminum powder metallurgy processing

    Energy Technology Data Exchange (ETDEWEB)

    Flumerfelt, J.F.

    1999-02-12

    The objective of this dissertation is to explore the hypothesis that there is a strong linkage between gas atomization processing conditions, as-atomized aluminum powder characteristics, and the consolidation methodology required to make components from aluminum powder. The hypothesis was tested with pure aluminum powders produced by commercial air atomization, commercial inert gas atomization, and gas atomization reaction synthesis (GARS). A comparison of the GARS aluminum powders with the commercial aluminum powders showed the former to exhibit superior powder characteristics. The powders were compared in terms of size and shape, bulk chemistry, surface oxide chemistry and structure, and oxide film thickness. Minimum explosive concentration measurements assessed the dependence of explosibility hazard on surface area, oxide film thickness, and gas atomization processing conditions. The GARS aluminum powders were exposed to different relative humidity levels, demonstrating the effect of atmospheric conditions on post-atomization processing conditions. The GARS aluminum powders were exposed to different relative humidity levels, demonstrating the effect of atmospheric conditions on post-atomization oxidation of aluminum powder. An Al-Ti-Y GARS alloy exposed in ambient air at different temperatures revealed the effect of reactive alloy elements on post-atomization powder oxidation. The pure aluminum powders were consolidated by two different routes, a conventional consolidation process for fabricating aerospace components with aluminum powder and a proposed alternative. The consolidation procedures were compared by evaluating the consolidated microstructures and the corresponding mechanical properties. A low temperature solid state sintering experiment demonstrated that tap densified GARS aluminum powders can form sintering necks between contacting powder particles, unlike the total resistance to sintering of commercial air atomization aluminum powder.

  2. Fluoride Importance in Controlling Caries and Fluorosis

    OpenAIRE

    Gaurav Solanki

    2012-01-01

    The use of fluorides for oral health has always involved a balance between the protective benefit against dental caries and the risk of developing fluorosis. The link between fluoride and dental health was established to determining the causes of dental fluorosis or enamel mottling. Fluorosis in Indian children was highly prevalent in the early 1990s. Policy were introduced to control fluoride exposure and to reduce the prevalence of fluorosis. The study aimed of describing the prevalence, se...

  3. Fluoride ions sorption of the water using natural and modified hematite with aluminium hydroxide; Sorcion de iones fluoruro del agua utilizando hematita natural y hematita acondicionada con hidroxido de aluminio

    Energy Technology Data Exchange (ETDEWEB)

    Teutli S, E. A.

    2011-07-01

    Fluorine is a mineral known for its dental benefits, but fluoride ions can cause fluoro sis in excessive quantities. There are many epidemiological studies on possible adverse effects resulting from prolonged ingestion of fluoride through drinking water. These studies demonstrate that fluoride mainly affects the bone tissue (bones and teeth), may produce an adverse effect on tooth enamel and can cause mild dental fluoro sis at concentrations from 0.9 to 1.2 mg/L in drinking water. In several states of Mexico, water contaminated with fluoride ions can be found, such as Aguascalientes, Chihuahua, Coahuila, Durango, Guanajuato, Sonora, Zacatecas, San Luis Potosi and Jalisco, where the fluoride ions levels are higher than 1.5 mg/L, established by the Mexican Official Standard (NOM-127-Ssa-2000) which sets the permissible limits of water for human use and consumption. Currently, several technologies have been proposed to remove fluoride ions from water such as precipitation methods which are based on the addition of chemicals to water and sorption methods to removed fluoride ions by sorption or ion exchange reactions by some suitable substrate capable of regenerate and reuse. In this work, the sorption of fluoride ions using unmodified and modified hematite with aluminum hydroxide to remove fluoride ions from water by bath experiments was studied. The hematite was modified by treating it with aluminum hydroxide, NaOH and Al{sub 2}(SO{sub 4}){sub 3} solutions. The characterization of hematite before and after modification with aluminum hydroxide was studied by X-ray diffraction, scanning electron microscopy, EDS and Bet. The effect of ph, contact time, concentration of fluoride ions, and the dose of sorbent on the sorption of fluoride ions by the modified hematite were studied. Equilibrium was reached within 48 hours of contact time and the maximum sorption of fluoride ions were in the range pH{sub eq} between 2.3 and 6.2. Sorption capacities of fluoride ions as a

  4. Effect of titanium tetrafluoride, amine fluoride and fluoride varnish on enamel erosion in vitro

    NARCIS (Netherlands)

    Vieira, A; Ruben, JL; Huysmans, MCDNJM

    2005-01-01

    This study aimed at evaluating the effect of 1 and 4% titanium tetrafluoride (TiF4) gels, amine fluoride (AmF) 1 and 0.25% and a fluoride varnish (FP) on the prevention of dental erosion. Two experimental groups served as controls, one with no pretreatment and another one pre-treated with a fluoride

  5. High fluoride exposure in hemodialysis patients.

    Science.gov (United States)

    Bello, V A; Gitelman, H J

    1990-04-01

    The observation of higher plasma flouride levels in our hemodialysis (HD) patients than our continuous ambulatory peritoneal dialysis (CAPD) patients (4.0 +/- 0.5 mumol/L [n = 17] v 2.5 +/- 0.3 mumol/L [n = 17], P less than 0.005) prompted an evaluation of fluoride metabolism during HD. We found that serum fluoride was completely ultrafiltrable across cuprophane membranes (99% +/- 4%) and that HD produced acute changes in plasma fluoride levels that correlated well with the fluoride gradient between plasma and dialysis fluid at the start of dialysis. Our HD fluids contained significantly higher fluoride concentrations than were present in commercially prepared peritoneal dialysis fluid. Our fluids are prepared from fluoridated tap water that is purified by reverse osmosis (RO). We conclude that the different concentrations of fluoride in our dialysis fluids account for the differences in the plasma flouride concentrations between our dialysis groups. Since many HD units rely on RO systems to purify fluoridated tap water, it is likely that many HD patients are being exposed inadvertently to increased concentrations of fluoride.

  6. In vitro Fluoride Release and Tensile Bond Strength of a Polymeric Intra-Buccal Bioadhesive

    OpenAIRE

    Vinicius PEDRAZZI; LARA, Elza Helena Guimaraes; PANZERI, Heitor; John H Collett; ISSA, Joao Paulo Mardegan

    2009-01-01

    The intra-buccal polymeric bioadhesive systems that can stay adhered to the oral soft tissues for drug programmed release, with the preventive and/or therapeutic purpose has been employed for large clinical situations. A system based on hydroxypropyl methyl cellulose/Carbopol 934`/magnesium stearate (HPMC/Cp/StMg) was developed having the sodium fluoride as active principle. This kind of system was evaluated according to its resistance to the removal by means of physical test of tensile stren...

  7. Relationship of phosphatidylinositol bisphosphate hydrolysis to calcium mobilization and functional activation in fluoride-treated neutrophils.

    OpenAIRE

    English, D.; Debono, D J; Gabig, T G

    1987-01-01

    Sodium fluoride (20 mM) effected rapid hydrolysis of phosphatidylinositol bisphosphate (PIP2) in human neutrophils. Intracellular free Ca2+ levels increased after PIP2 hydrolysis but before respiratory burst activation. Both the increase in intracellular free Ca2+ levels and the extent of functional activation were dependent on the availability of extracellular Ca2+. The rate of F(-)-stimulated PIP2 hydrolysis, however, was not affected when the rise in cytosolic Ca2+ was severely limited by ...

  8. ALUMINUM AND CHROMIUM LEACHING WORKSHOP WHITEPAPER

    Energy Technology Data Exchange (ETDEWEB)

    McCabe, D; Jeff Pike, J; Bill Wilmarth, B

    2007-04-25

    formulations. Disposal of the resulting aluminum and chromium-rich streams are different at the two sites, with vitrification into Low Activity Waste (LAW) glass at Hanford, and solidification in Saltstone at SRS. Prior to disposal, the leachate solutions must be treated to remove radionuclides, resulting in increased operating costs and extended facility processing schedules. Interim storage of leachate can also add costs and delay tank closure. Recent projections at Hanford indicate that up to 40,000 metric tons of sodium would be needed to dissolve the aluminum and maintain it in solution, which nearly doubles the amount of sodium in the entire current waste tank inventory. This underscores the dramatic impact that the aluminum leaching can have on the entire system. A comprehensive view of leaching and the downstream impacts must therefore be considered prior to implementation. Many laboratory scale tests for aluminum and chromium dissolution have been run on Hanford wastes, with samples from 46 tanks tested. Three samples from SRS tanks have been tested, out of seven tanks containing high aluminum sludge. One full-scale aluminum dissolution was successfully performed on waste at SRS in 1982, but generated a very large quantity of liquid waste ({approx}3,000,000 gallons). No large-scale tests have been done on Hanford wastes. Although the data to date give a generally positive indication that aluminum dissolution will work, many issues remain, predominantly because of variable waste compositions and changes in process conditions, downstream processing, or storage limitations. Better approaches are needed to deal with the waste volumes and limitations on disposal methods. To develop a better approach requires a more extensive understanding of the kinetics of dissolution, as well as the factors that effect rates, effectiveness, and secondary species. Models of the dissolution rate that have been developed are useful, but suffer from limitations on applicable compositional

  9. 化学增强铝硅酸盐玻璃扩散性能研究%The Diffusion Performance of Potassium and Sodium in Ion Exchanged Aluminum Silicate Glass

    Institute of Scientific and Technical Information of China (English)

    程金树; 赵薇; 肖子凡

    2012-01-01

    了解碱金属离子在玻璃表面的扩散对生产高强度铝硅酸盐系统离子交换玻璃具有重要意义.通过外加Al,讨论不同Al/Na对碱离子扩散影响.采用EPMA测得玻璃断面K+、Na+分布曲线,根据Boltzmann- Matano计算方法得到K+、Na+的扩散系数,根据Arrhenius公式计算得到K+、Na+的扩散活化能.实验证明,随着Al/Na的增加,K+、Na+扩散深度逐渐增加,互扩散系数逐渐增加,K+、Na+平均活化能逐渐增加.讨论玻璃体内Al/Na比例是研究高强度离子交换玻璃的一个重要方向.%In the production of ion exchanged aluminum silicate system glass, the alkali ion diffusion on the glass surface is an important process which must be considered. In this paper, we discussed the impact of additional Al on the diffusion of alkali ions. The penetration depth profiles of alkali ions were obtained by EPMA methods. The diffusion coefficients of alkali ions were calculated by Boltzmann-Matano equation. And the active energy of alkali ions were gotten by Arrhenius equation. The results showed that the penetration depth, the interdiffusion coefficient and the average active energy increased with the increase of Al/Na ratios. It means the Al/Na ratios have a great effect on the diffusion of alkali i-ons.

  10. Effects of different kinds of fluorides on enolase and ATPase activity of a fluoride-sensitive and fluoride-resistant Streptococcus mutans strain

    NARCIS (Netherlands)

    van Loveren, C.; Hoogenkamp, M.A.; Deng, D.M.; ten Cate, J.M.

    2008-01-01

    Enolase and ATPase are sensitive to fluoride. It is unclear whether this sensitivity differs for F-sensitive and F-resistant cells or for different types of fluoride. Permeabilized cells of the fluoride-sensitive strain Streptococcus mutans C180-2 and its fluoride-resistant mutant strain C180-2 FR w

  11. Contamination of fluoride in groundwater and its effect on human health: a case study in hard rock aquifers of Siddipet, Telangana State, India

    Science.gov (United States)

    Narsimha, A.; Sudarshan, V.

    2016-06-01

    Hydrogeochemical investigation has been carried out in the granitic terrain of Siddipet area, Medak district, Telangana State, India with an aim to understand the distribution of fluoride in the groundwater and to understand the relationship of fluoride with other major ions, and also to identify the high fluoride-bearing groundwater zones. 104 groundwater samples were analyzed in the study area for fluoride and other major ions like calcium, magnesium, chloride, carbonate, bicarbonate, sodium, potassium, sulfate, and nitrate in addition to pH and electrical conductivity. The studies revealed that the concentration of fluoride in groundwater is ranging from 0.2 to 2.2 mg L-1 with a mean of 1.1 mg L-1. Nearly 22 % of groundwater has more than the permissible limit of fluoride (1.5 mg L-1), which is responsible for the endemic dental fluorosis in the area concerned. Geochemical classification of groundwater shows that Na-HCO3, Ca-Cl, and Ca-HCO3-Na are the dominant hydrochemical facies. Gibbs diagram shows rock-water interaction dominance and evaporation dominance, which are responsible for the change in the quality of water in the hard rock aquifer of the study area. The groundwater in villages and its environs are affected by fluoride contamination, and consequently majority of the population living in these villages suffer from dental fluorosis. Hence, they are advised to consume drinking water which has less than 1.5 mg L-1 fluoride to avoid further fluorosis risks.

  12. A prospective, randomized placebo-controlled clinical trial on the effects of a fluoride rinse on white spot lesion development and bleeding in orthodontic patients.

    Science.gov (United States)

    van der Kaaij, Nicoline C W; van der Veen, Monique H; van der Kaaij, Marleen A E; ten Cate, Jacob M

    2015-06-01

    Demineralizations around orthodontic brackets are a main disadvantage of orthodontic treatment. Several methods have been advocated to prevent their development, such as fluoride rinses or varnishes. In this randomized clinical trial, a fluoride rinse (a combination of sodium fluoride and amine fluoride) was compared with a placebo rinse, to be used every evening after toothbrushing. A total of 81 participants (mean age: 13.3 yr) completed the study (mean treatment period: 24.5 months). Demineralizations, measured using quantitative light-induced fluorescence and the decayed, missing, and filled surfaces (DMFS) index, were assessed before treatment (baseline) and around 6 wk after debonding (post treatment). Bleeding scores were measured at baseline, and during and post treatment. The incidence rate ratio for demineralizations was 2.6 (95% CI: 1.1-6.3) in the placebo group vs. the fluoride group. In the fluoride group, 31% of participants developed at least one demineralization, compared with 47% in the placebo group. Relative to baseline, gingival bleeding increased significantly in the placebo group 1 yr after the start of treatment and onwards. For the fluoride group, bleeding scores during treatment were not different from those at baseline. In conclusion, using a fluoride rinse helps to maintain better oral health during fixed appliance treatment, resulting in fewer demineralizations.

  13. Is the Aluminum Hypothesis Dead?

    OpenAIRE

    Lidsky, Theodore I.

    2014-01-01

    The Aluminum Hypothesis, the idea that aluminum exposure is involved in the etiology of Alzheimer disease, dates back to a 1965 demonstration that aluminum causes neurofibrillary tangles in the brains of rabbits. Initially the focus of intensive research, the Aluminum Hypothesis has gradually been abandoned by most researchers. Yet, despite this current indifference, the Aluminum Hypothesis continues to attract the attention of a small group of scientists and aluminum continues to be viewed w...

  14. High energy density aluminum battery

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Gilbert M.; Paranthaman, Mariappan Parans; Dai, Sheng; Dudney, Nancy J.; Manthiram, Arumugan; McIntyre, Timothy J.; Sun, Xiao-Guang; Liu, Hansan

    2016-10-11

    Compositions and methods of making are provided for a high energy density aluminum battery. The battery comprises an anode comprising aluminum metal. The battery further comprises a cathode comprising a material capable of intercalating aluminum or lithium ions during a discharge cycle and deintercalating the aluminum or lithium ions during a charge cycle. The battery further comprises an electrolyte capable of supporting reversible deposition and stripping of aluminum at the anode, and reversible intercalation and deintercalation of aluminum or lithium at the cathode.

  15. Organic electrolytes for sodium batteries

    Science.gov (United States)

    Vestergaard, B.

    1992-09-01

    A summary of earlier given status reports in connection with the project on organic electrolytes for sodium batteries is presented. The aim of the investigations was to develop new room temperature molten salts electrolytes mainly with radical substituted heterocyclic organic chlorides mixed with aluminum chloride. The new electrolytes should have an ionic conductivity comparable with MEIC1:AlCl3 or better. A computer model program MOPAC (Molecular Orbital Package) was to be included to calculate theoretically reduction potentials for a variety of organic cations. Furthermore, MOPAC could be utilized to predict the electron densities, and then give a prediction of the stability of the organic cation.

  16. Anomalous distribution of fluoride and phosphorus forms in surface sediments along eastern Egyptian Mediterranean Sea coast.

    Science.gov (United States)

    El-Said, Ghada F; Khalil, Mona Kh; Draz, Suzanne E O

    2016-07-01

    The study focused on the distribution of fluoride, total phosphorus, and four phosphorus fractions in some sites along the Egyptian Mediterranean Sea coast. The geochemical parameters and textures of 30 surficial sediment samples from six sectors were determined. The sediment's geochemical parameters (total carbonates (TCO3) and total organic carbon (TOC), exchangeable and carbonate-associated phosphorus (Pex), iron- and aluminum-associated phosphorus (POH), calcium-associated phosphate/apatite (PHCl), residual phosphorus (PR), total phosphorus (TP), calcium (Cas), magnesium (Mgs), and fluoride (Fs)) showed variable values. The rank of phosphorus fractions in the sediments PHCl > PR > POH > Pex reflected that the eastern Egyptian coast was still uncontaminated. Generally, Pex levels gave a gradual increase in the offshore direction, while POH values varied along the stations of each sector. Also, the presented data indicated that the apatite-P fraction was the main storage of the phosphate in the sediments with a contribution to TP ranging from 58 to 87 %. The highest and lowest average fluoride contents (0.49 ± 0.10 and 0.25 ± 0.31 mg/g) were determined in the Port Said and Damietta sectors, respectively. Interestingly, the variability of both phosphorus and fluoride levels in the investigated area seemed to be accompanied with the sediment's character beside the proximity to potential effluent sources.

  17. Is the Aluminum Hypothesis dead?

    Science.gov (United States)

    Lidsky, Theodore I

    2014-05-01

    The Aluminum Hypothesis, the idea that aluminum exposure is involved in the etiology of Alzheimer disease, dates back to a 1965 demonstration that aluminum causes neurofibrillary tangles in the brains of rabbits. Initially the focus of intensive research, the Aluminum Hypothesis has gradually been abandoned by most researchers. Yet, despite this current indifference, the Aluminum Hypothesis continues to attract the attention of a small group of scientists and aluminum continues to be viewed with concern by some of the public. This review article discusses reasons that mainstream science has largely abandoned the Aluminum Hypothesis and explores a possible reason for some in the general public continuing to view aluminum with mistrust.

  18. Impact Of Sodium Oxalate, Sodium Aluminosilicate, and Gibbsite/Boehmite on ARP Filter Performance

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Burket, P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-11-01

    The Savannah River Site (SRS) is currently treating radioactive liquid waste with the Actinide Removal Process (ARP) and the Modular Caustic Side Solvent Extraction Unit (MCU). Recently, the low filter flux through the ARP of approximately 5 gallons per minute has limited the rate at which radioactive liquid waste can be treated. Salt Batch 6 had a lower processing rate and required frequent filter cleaning. Savannah River Remediation (SRR) has a desire to understand the causes of the low filter flux and to increase ARP/MCU throughput. SRR requested SRNL to conduct bench-scale filter tests to evaluate whether sodium oxalate, sodium aluminosilicate, or aluminum solids (i.e., gibbsite and boehmite) could be the cause of excessive fouling of the crossflow or secondary filter at ARP. The authors conducted the tests by preparing slurries containing 6.6 M sodium Salt Batch 6 supernate, 2.5 g MST/L slurry, and varying concentrations of sodium oxalate, sodium aluminosilicate, and aluminum solids, processing the slurry through a bench-scale filter unit that contains a crossflow primary filter and a dead-end secondary filter, and measuring filter flux and transmembrane pressure as a function of time. Among the conclusions drwn from this work are the following: (1) All of the tests showed some evidence of fouling the secondary filter. This fouling could be from fine particles passing through the crossflow filter. (2) The sodium oxalate-containing feeds behaved differently from the sodium aluminosilicate- and gibbsite/boehmite-containing feeds.

  19. Anodizing Aluminum with Frills.

    Science.gov (United States)

    Doeltz, Anne E.; And Others

    1983-01-01

    "Anodizing Aluminum" (previously reported in this journal) describes a vivid/relevant laboratory experience for general chemistry students explaining the anodizing of aluminum in sulfuric acid and constrasting it to electroplating. Additions to this procedure and the experiment in which they are used are discussed. Reactions involved are…

  20. Fluoride intake and its safety among heavy tea drinkers in a British fluoridated city.

    Science.gov (United States)

    Jenkins, G N

    1991-01-01

    Tea-drinking in very young children has been studied in a British city. The results suggested that the fluoride in tea would, in some cases, be sufficient to influence caries. Clinical findings to some extent supported this. The main purpose of the investigation reported here was to determine maximum possible fluoride intake in adults who were heavy tea drinkers in a fluoridated city and relate it to toxic thresholds. Heavy tea drinkers were traced through Health Visitors and voluntary organizations and the volumes and fluoride concentrations of their drinks were measured. Even the highest intake found (9 mg) is below the probable intake in Bartlett, Texas (8 ppm of fluoride), in relation to which no undesirable symptoms have been reported (Leone et al. 1954). This confirms the safety of fluoridation. The effects on fluoride concentration of evaporating soft and hard fluoride-containing waters to small bulk were compared. The results showed ceilings of 3 ppm of fluoride in hard water and about 14 ppm in soft water, much higher than the levels expected on the basis of the usually stated solubility of CaF2 (16 or 8 ppm of fluoride). However, under normal household conditions, it is most unlikely that dangerous levels of fluoride would be ingested from boiled water.

  1. The aluminum smelting process.

    Science.gov (United States)

    Kvande, Halvor

    2014-05-01

    This introduction to the industrial primary aluminum production process presents a short description of the electrolytic reduction technology, the history of aluminum, and the importance of this metal and its production process to modern society. Aluminum's special qualities have enabled advances in technologies coupled with energy and cost savings. Aircraft capabilities have been greatly enhanced, and increases in size and capacity are made possible by advances in aluminum technology. The metal's flexibility for shaping and extruding has led to architectural advances in energy-saving building construction. The high strength-to-weight ratio has meant a substantial reduction in energy consumption for trucks and other vehicles. The aluminum industry is therefore a pivotal one for ecological sustainability and strategic for technological development.

  2. Review on fluoride, with special emphasis on calcium fluoride mechanisms in caries prevention.

    Science.gov (United States)

    ten Cate, J M

    1997-10-01

    Low concentrations of fluoride have a beneficial effect on enamel and dentin de- and remineralization. After fluoride treatments, such as topical applications, rinses or dentifrices, salivary fluoride concentrations decrease exponentially in a biphasic manner to very low concentrations within a few hours. For treatments to be effective over periods longer than the brushing and the following salivary clearance, fluoride needs to be deposited and slowly released. Calcium fluoride (or like) deposits act in such a way, owing to a surface covering of phosphate and/or proteins, which makes the CaF2 less soluble under in vivo conditions than in a pure form in inorganic solutions. Moreover, due to the phosphate groups on the surface of the calcium fluoride globules, fluoride is assumed to be released with decreasing pH when the phosphate groups are protonated in the dental plaque.

  3. Coupling a PEM fuel cell and the hydrogen generation from aluminum waste cans

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Susana Silva; Albanil Sanchez, Loyda; Alvarez Gallegos, Alberto A. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Av. Universidad 1001, Col. Chamilpa, Cuernavaca, Mor. CP 62210 (Mexico); Sebastian, P.J. [Centro de Investigacion en Energia-UNAM, 62580 Temixco, Morelos (Mexico); Cuerpo Academico de Energia y Sustentabilidad, UPCH, Tuxtla Gutierrez, Chiapas (Mexico)

    2007-10-15

    High purity hydrogen was generated from the chemical reaction of aluminum and sodium hydroxide. The aluminum used in this study was obtained from empty soft drink cans and treated with concentrated sulfuric acid to remove the paint and plastic film. One gram of aluminum was reacted with a solution of 2moldm{sup -3} of sodium hydroxide to produce hydrogen. The hydrogen produced from aluminum cans and oxygen obtained from a proton exchange membrane electrolyzer or air, was fed to a proton exchange membrane (PEM) fuel cell to produce electricity. Yields of 44 mmol of hydrogen contained in a volume of 1.760dm{sup 3} were produced from one gram of aluminum in a time period of 20 min. (author)

  4. Effect of fluoride on nickel-titanium and stainless steel orthodontic archwires: an in-vitro study.

    Directory of Open Access Journals (Sweden)

    Farzin Heravi

    2015-02-01

    Full Text Available The commonly used Nickel-Titanium (NiTi archwires in orthodontic treatment are often exposed to fluoride-containing mouthwashes. The aim of this in-vitro study was to evaluate and compare the corrosion resistance of three commercially available NiTi archwires exposed to 0.05 wt% and 0.2 wt% fluoride mouthwashes.Three different types of NiTi archwires, 0.016″ in diameter, from Dentaurum, Global, and GAC, and a stainless steel archwire from Dentaurum were examined to assess their corrosion resistance in Fusayama-Meyer artificial saliva and in two other artificial saliva containing 0.05 wt% and 0.2 wt% sodium fluoride (NaF. After the primary setup of wires, they were tested by potentiodynamic and potentiostatic polarization and corrosion potential/time analyses. Their surfaces were evaluated using a scanning electronic microscope (SEM.The results showed that all the wires were passive in artificial saliva. In contrast, by adding fluoride ions to the solution, the decrease in the archwires' corrosion resistance was in direct proportion to the increase in fluoride concentration.The NiTi wires experienced deterioration of their corrosion properties under the effect of fluoride but not as much as the stainless steel archwires.

  5. HOUSEHOLD PURIFICATION OF FLUORIDE CONTAMINATED MAGADI (TRONA)

    DEFF Research Database (Denmark)

    1997-01-01

    Purification of fluoride contaminated magadi is studied using bone char sorption and calcium precipitation. The bone char treatment is found to be workable both in columns and in batches where the magadi is dissolved in water prior to treatment. The concentrations in the solutions were 89 g magadi...... treatment method. A procedure for purification of fluoride contaminated magadi at household level is described....

  6. Determination of fluoride content in drinking water and tea infusions using fluoride ion selective electrode

    Directory of Open Access Journals (Sweden)

    Rajković Miloš B.

    2007-01-01

    Full Text Available Potentiometric analysis of fluoride content (as F- ion in solutions by using fluoride ion-selective electrode is simple, reliable and cheap. Very small concentrations of fluoride-ions (to 10-6 mol/dm3 can be determined by fluoride selective electrode, with regulation of ion strength of a solution and control of concentration of hydroxide ions and interfering ions of metals. The influence of pH and complexing ions of metals can be successfully regulated by the TISAB solution and by preserving pH value in the range from 5.00 to 7.00. The content of fluorides in the samples can be determined by the method of direct potentiometer, and in the case of very low concentration by standard addition method. In this paper it was analyzed the determination of fluoride ions concentration in bottled mineral waters and water from Belgrade plumbing in two Belgrade districts (Palilula and Novi Beograd and in tea, by using the fluoride selective electrode. It was determined that the content of fluoride ions in bottled mineral water significantly differs from values given on declaration, and that content of fluoride ions varies over a period of time. The content of fluoride ions in water from plumbing in two Belgrade districts at the time of analysis was significantly increased and exceeded values given in Regulation for drinking water quality. The received results from the analysis of fluorides in teas show that fluorides exist in teas in different concentrations. There are also differences between the same kinds of tea, which is noted with mint (Mentha piperitae folium, as a consequence of differences between soils where it was planted. As taking of fluorides, according to World Health Organisation recommendation (WHO, is limited in the range from 2 to 4 mg per day, it is necessary to give the content of fluorides on all products that are used in human consumption.

  7. Diethylenetriaminium hexafluoridotitanate(IV fluoride

    Directory of Open Access Journals (Sweden)

    J. Lhoste

    2008-11-01

    Full Text Available The title compound, (C6H21N4[TiF6]F, was synthesized by the reaction of TiO2, tris(2-aminoethylamine, HF and ethanol at 463 K in a microwave oven. The crystal structure consists of two crystallographically independent [TiF6]2− anions, two fluoride anions and two triply-protonated tris(2-aminoethylamine cations. The Ti atoms are coordinated by six F atoms within slightly distorted octahedra. The anions and cations are connected by intermolecular N—H...F hydrogen bonds.

  8. Test Your Sodium Smarts

    Science.gov (United States)

    ... You may be surprised to learn how much sodium is in many foods. Sodium, including sodium chloride ... foods with little or no salt. Test your sodium smarts by answering these 10 questions about which ...

  9. Fluoride-elicited developmental testicular toxicity in rats: Roles of endoplasmic reticulum stress and inflammatory response

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Shun [Department of Environmental Health and MOE Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Hangkong Road 13, Wuhan 430030, Hubei (China); Jiang, Chunyang [Department of Environmental Health and MOE Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Hangkong Road 13, Wuhan 430030, Hubei (China); Department of Thoracic Surgery, Tianjin Union Medicine Centre, 190 Jieyuan Road, Hongqiao District, Tianjin 300121, Tianjin (China); Liu, Hongliang [Tianjin Center for Disease Control and Prevention, Huayue Road 6, Hedong Region, Tianjin 300011, Tianjin (China); Guan, Zhizhong [Department of Pathology, Guiyang Medical College, Guiyang 550004, Guizhou (China); Zeng, Qiang [Tianjin Center for Disease Control and Prevention, Huayue Road 6, Hedong Region, Tianjin 300011, Tianjin (China); Zhang, Cheng; Lei, Rongrong; Xia, Tao; Gao, Hui; Yang, Lu; Chen, Yihu; Wu, Xue; Zhang, Xiaofei [Department of Environmental Health and MOE Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Hangkong Road 13, Wuhan 430030, Hubei (China); Cui, Yushan; Yu, Linyu [Tianjin Center for Disease Control and Prevention, Huayue Road 6, Hedong Region, Tianjin 300011, Tianjin (China); Wang, Zhenglun [Department of Environmental Health and MOE Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Hangkong Road 13, Wuhan 430030, Hubei (China); Wang, Aiguo, E-mail: wangaiguo@mails.tjmu.edu.cn [Department of Environmental Health and MOE Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Hangkong Road 13, Wuhan 430030, Hubei (China)

    2013-09-01

    Long-term excessive fluoride intake is known to be toxic and can damage a variety of organs and tissues in the human body. However, the molecular mechanisms underlying fluoride-induced male reproductive toxicity are not well understood. In this study, we used a rat model to simulate the situations of human exposure and aimed to evaluate the roles of endoplasmic reticulum (ER) stress and inflammatory response in fluoride-induced testicular injury. Sprague–Dawley rats were administered with sodium fluoride (NaF) at 25, 50 and 100 mg/L via drinking water from pre-pregnancy to gestation, birth and finally to post-puberty. And then the testes of male offspring were studied at 8 weeks of age. Our results demonstrated that fluoride treatment increased MDA accumulation, decreased SOD activity, and enhanced germ cell apoptosis. In addition, fluoride elevated mRNA and protein levels of glucose-regulated protein 78 (GRP78), inositol requiring ER-to-nucleus signal kinase 1 (IRE1), and C/EBP homologous protein (CHOP), indicating activation of ER stress signaling. Furthermore, fluoride also induced testicular inflammation, as manifested by gene up-regulation of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), in a nuclear factor-κB (NF-κB)-dependent manner. These were associated with marked histopathological lesions including injury of spermatogonia, decrease of spermatocytes and absence of elongated spermatids, as well as severe ultrastructural abnormalities in testes. Taken together, our results provide compelling evidence that ER stress and inflammation would be novel and significant mechanisms responsible for fluoride-induced disturbance of spermatogenesis and germ cell loss in addition to oxidative stress. - Highlights: • We used a rat model to simulate the situations of human fluoride (F) exposure. • Developmental F exposure induces testicular damage related with oxidative stress.

  10. Spectra of sodium aluminate solutions

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The UV spectra of sodium aluminate solutions were obtained in the sodium oxide concentration range from 59 to 409 g/L and the caustic ratio range from 1.5 to 4.0 to reveal the structure characteristics of them. It is found that a new peak appears at about 370 nm besides peaks at about 220 and 266 nm in all solutions. The new peak is strongly favored by high hydroxide concentration and high caustic ratio. And it only appears when the solutions are prepared by dissolving sodium hydroxide and aluminum hydroxide.In addition, the IR and Raman spectra of sodium aluminate solutions with high alkali concentration and high caustic ratio were measured, and the UV spectra of aqueous solutions of Al(H2O)63+ and AlF63- were measured as well. According to the crystal field theory in coordination chemistry as well as the above spectra characteristics, this new peak at about 370 nm is determined as the evidence of a new species of aluminate ion with a coordination number of 6.

  11. Clinical biochemistry of aluminum

    Energy Technology Data Exchange (ETDEWEB)

    King, S.W.; Savory, J.; Wills, M.R.

    1981-05-01

    Aluminum toxicity has been implicated in the pathogenesis of a number of clinical disorders in patients with chronic renal failure on long-term intermittent hemodialysis treatment. The predominant disorders have been those involving either bone (osteomalacic dialysis osteodystrophy) or brain (dialysis encephalopathy). In nonuremic patients, an increased brain aluminum concentration has been implicated as a neurotoxic agent in the pathogenesis of Alzheimer's disease and was associated with experimental neurofibrillary degeneration in animals. The brain aluminum concentrations of patients dying with the syndrome of dialysis encephalopathy (dialysis dementia) are significantly higher than in dialyzed patients without the syndrome and in nondialyzed patients. Two potential sources for the increased tissue content of aluminum in patients on hemodialysis have been proposed: (1) intestinal absorption from aluminum containing phosphate-binding gels, and (2) transfer across the dialysis membrane from aluminum in the water used to prepare the dialysate. These findings, coupled with our everyday exposure to the ubiquitous occurrence of aluminum in nature, have created concerns over the potential toxicity of this metal.

  12. Low sodium diet (image)

    Science.gov (United States)

    ... for you. Look for these words on labels: low-sodium, sodium-free, no salt added, sodium-reduced, or ... for you. Look for these words on labels: low-sodium, sodium-free, no salt added, sodium-reduced, or ...

  13. Sodium movements in perfused squid giant axons. Passive fluxes.

    Science.gov (United States)

    Rojas, E; Canessa-Fischer, M

    1968-08-01

    Sodium movements in internally perfused giant axons from the squid Dosidicus gigas were studied with varying internal sodium concentrations and with fluoride as the internal anion. It was found that as the internal concentration of sodium was increased from 2 to 200 mM the resting sodium efflux increased from 0.09 to 34.0 pmoles/cm(2)sec and the average resting sodium influx increased from 42.9 to 64.5 pmoles/cm(2)sec but this last change was not statistically significant. When perfusing with a mixture of 500 mM K glutamate and 100 mM Na glutamate the resting efflux was 10 +/- 3 pmoles/cm(2)sec and 41 +/- 10 pmoles/cm(2)sec for sodium influx. Increasing the internal sodium concentration also increased both the extra influx and the extra efflux of sodium due to impulse propagation. At any given internal sodium concentration the net extra influx was about 5 pmoles/cm(2)impulse. This finding supports the notion that the inward current generated in a propagated action potential can be completely accounted for by movements of sodium.

  14. An in vitro evaluation of the efficacy of a novel iontophoresis fluoride tray on remineralization

    Science.gov (United States)

    Ulusu, Tezer

    2014-01-01

    Objectives: The aim of this study is to determine the effects on remineralization of a novel iontophoresis device called ‘Fluorinex’, conventional (acidulated phosphat fluoride) APF gel treatment, and conventional ionthophoresis device comparatively by laser fluorescence measurements. Study Design: Artificial incipient carious lesions were created on immature, 60 intact premolar and molar teeth with no defects. The specimens were randomly allocated to four groups. In the first group 1.23% APF gel was applied to specimens by conventional method for 4 minutes and in the second group 2% (sodium fluoride) NaF solution applied by conventional iontophoresis device for 4 minutes. In Fluorinex group specimens were pretreated with (copper chloride) CuCl2 for 1 minute and then treated for 4 minutes with 1.23% APF gel in a Fluoritray. Control group was placed in distilled water for 4 minutes. After these applications all specimens were included to a pH cycling. DIAGNOdent pen measurement were obtained in three different time intervals; after incipient carious lesions, after fluoride treatments and after pH cycling. Specimens were studied by SEM(scanning electron microscopy) after artificial caries lesions and fluoride treatments. Results: Alterations on DIAGNOdent pen measurements before and after treatment, the Fluorinex group was statistically different from conventional APF gel (p=0.011), conventional NaF iontophoresis (pDIAGNOdent pen measurements before treatment and after pH cycling were compared, differences were statistically significant in Fluorinex and conventional APF gel groups (p<0.001). Conclusions: The results of this in vitro study has shown that fluoride application by Fluorinex was superior to the conventional APF gel application and NaF iontophoresis on incipient carious lesions. Key words:Fluoride, iontophoresis, remineralization. PMID:25593651

  15. The effect of monoalkyl phosphates and fluoride on dissolution of hydroxyapatite, and interactions with saliva.

    Science.gov (United States)

    Jones, S B; Rees, G D; Shellis, R P; Barbour, M E

    2013-01-01

    The aims were to investigate the effect of monoalkyl phosphates (MAPs) and fluoride on dissolution rate of native and saliva-coated hydroxyapatite (HA). Fluoride at 300 mg/l (as NaF) inhibited dissolution of native HA by 12%, while potassium and sodium dodecyl phosphates (PDP, SDP), at 0.1% or higher, inhibited dissolution by 26-34%. MAPs, but not fluoride, also showed persistence of action. MAPs at 0.5% and fluoride at 300 mg/l were then tested separately against HA pre-treated with human saliva for 2 or 18 h. Agents were applied with brushing to half the specimens, and without brushing to the other half. In control (water-treated) specimens, pre-treatment of HA with human saliva reduced dissolution rate on average by 41% (2 h) and 63% (18 h). Brushing did not have a statistically significant effect on dissolution rate of saliva-coated specimens. In brushed specimens, fluoride significantly increased the inhibition due to 2- or 18-hour saliva pre-treatment. It is hypothesised that brushing partially removes the salivary film and allows KOH-soluble calcium fluoride formation at the surfaces of HA particles. Inhibition was reduced by PDP in 2-hour/non-brushed specimens and in 18-hour/brushed specimens. PDP did not affect dissolution rates in the remaining groups and SDP did not affect dissolution rate in any group. Possible reasons for these variable results are discussed. The experiments show that pre-treatment with saliva can significantly modify results of tests on potential anti-erosive agents and it is recommended that saliva pre-treatment should be a routine part of testing such agents.

  16. Effect of fluoride on oxidative phosphorylation and dehydrogenase systems in higher plants

    Energy Technology Data Exchange (ETDEWEB)

    Lovelace, C.J.

    1966-01-01

    Studies were conducted on the in vitro effect of fluoride on the succinic oxidase system utilizing mitochondria obtained from cauliflower. Methods are described for extracting mitochondria and determining maximum activities and inhibition using various treatments. Experiments were conducted in the absence of fluoride and using various concentrations of phosphate to determine the effect of phosphate alone on the succinic 2.6-dichlorophenolindophenol reductase component of the succinic oxidase system. These studies showed that phosphate had only slight effects on succinic 2.6-dichlorophenolindophenol reductase. An oxidative phosphorylation study was conducted to determine effects of fluoride on phosphorus esterification and oxygen uptake. It was found in general that respiration and phosphorylation were inhibited. The effects of phosphate in the presence of sodium fluoride were studied using various concentrations of phosphate. It was found that the middle range of phosphate concentrations used in these studies inhibited oxidation to a greater degree than at the extremes. An increased oxygen uptake at higher concentrations was observed. In vivo effects of fluoride on TCA cycle dehydrogenase enzymes of Pelargonium zonale were studied using p-nitro-blue-tetrazoleum chloride. Plants were exposed to 17 ppb HF and enzyme activities were compared to control plants. Leaves of control plants were also incubated in 5 X 10/sup -3/ M NaF. Injury observed in both fumigation and solution experiments was similar. Leaf tissue subjected to HF or NaF had less succinic p-nitro-blue-tetrazoleum chloride reductase activity than did the control tissue. Other Kreb's acid dehydrogenases were not inhibited by fluoride concentrations used in these experiments.

  17. Acid demineralization susceptibility of dental enamel submitted to different bleaching techniques and fluoridation regimens.

    Science.gov (United States)

    Salomão, Dlf; Santos, Dm; Nogueira, Rd; Palma-Dibb, Rg; Geraldo-Martins, Vr

    2014-01-01

    The aim of the current study was to assess the acid demineralization susceptibility of bleached dental enamel submitted to different fluoride regimens. One hundred bovine enamel blocks (6×6×3 mm) were randomly divided into 10 groups (n=10). Groups 1 and 2 received no bleaching. Groups 3 to 6 were submitted to an at-home bleaching technique using 6% hydrogen peroxide (HP; G3 and G4) or 10% carbamide peroxide (CP; G5 and G6). Groups 7 to 10 were submitted to an in-office bleaching technique using 35% HP (G7 and G8) or 35% CP (G9 and G10). During bleaching, a daily fluoridation regimen of 0.05% sodium fluoride (NaF) solution was performed on groups 3, 5, 7, and 9, while weekly fluoridation with a 2% NaF gel was performed on groups 4, 6, 8, and 10. The samples in groups 2 to 10 were pH cycled for 14 consecutive days. The samples from all groups were then assessed by cross-sectional Knoop microhardness at different depths from the outer enamel surface. The average Knoop hardness numbers (KHNs) were compared using one-way analysis of variance and Tukey tests (α=0.05). The comparison between groups 1 and 2 showed that the demineralization method was effective. The comparison among groups 2 to 6 showed the same susceptibility to acid demineralization, regardless of the fluoridation method used. However, the samples from groups 8 and 10 showed more susceptibility to acid demineralization when compared with group 2 (penamel to acid demineralization. However, the use of 35% HP and 35% CP must be associated with a daily fluoridation regimen, otherwise the in-office bleaching makes the bleached enamel more susceptible to acid demineralization.

  18. Corrosion behavior of zirconia in acidulated phosphate fluoride

    Directory of Open Access Journals (Sweden)

    Anie Thomas

    2016-02-01

    Full Text Available ABSTRACT Objective The corrosion behavior of zirconia in acidulated phosphate fluoride (APF representing acidic environments and fluoride treatments was studied. Material and Methods Zirconia rods were immersed in 1.23% and 0.123% APF solutions and maintained at 37°C for determined periods of time. Surfaces of all specimens were imaged using digital microscopy and scanning electron microscopy (SEM. Sample mass and dimensions were measured for mass loss determination. Samples were characterized by powder X-ray diffraction (XRD to detect changes in crystallinity. A biosensor based on electrochemical impedance spectroscopy (EIS was used to detect ion dissolution of material into the immersion media. Results Digital microscopy revealed diminishing luster of the materials and SEM showed increased superficial corrosion of zirconia submerged in 1.23% APF. Although no structural change was found, the absorption of salts (sodium phosphate onto the surface of the materials bathed in 0.123% APF was significant. EIS indicated a greater change of impedance for the immersion solutions with increasing bathing time. Conclusion Immersion of zirconia in APF solutions showed deterioration limited to the surface, not extending to the bulk of the material. Inferences on zirconia performance in acidic oral environment can be elucidated from the study.

  19. Effect of impurities in industrial salts on aluminum scrap melting

    Energy Technology Data Exchange (ETDEWEB)

    Ye, J.; Sahai, Y. [Ohio State Univ., Columbus, OH (United States). Dept. of Materials Science and Engineering; Revet, A. [Kalium Canada, ltd., Regina, Saskatchewan (Canada)

    1996-10-01

    Aluminum scrap such as Used Beverage Containers (UBC) is melted under a protective molten salt cover. An appropriate salt protects metal from oxidation, promotes coalescence of molten droplets, and separates clean metal from the oxide contamination. Generally, the salt compositions for aluminum scrap recycling are based on equimolar mixtures of NaCl and KCl. A small amount of fluoride is also added in the salt. In the past, laboratory research at universities and industrial laboratories have been limited to pure salts. However, the industrial salts have impurities such as sulfates and other insoluble materials. These impurities have a pronounced effect on the efficiency of the scrap remelting process. In this paper, the role of impurities in industrial salts in terms of their chemical interactions with the metal are summarized. The efficiency of different industrial grade salts containing varying amounts of sulfates and other insoluble impurities for scrap recycling is compared.

  20. Fluoride Programs in the School Setting: Preventive Dental Health.

    Science.gov (United States)

    Rebich, Theodore, Jr.; And Others

    1982-01-01

    Two types of school-based programs that increase students' use of fluoride for preventive dental health are described. In fluoride mouthrinse programs, teachers give their students a fluoride solution once a week in a paper cup. In areas where the level of fluoride in the water supply is insufficient, the flouride tablet program is used. (JN)

  1. Physiologic Conditions Affect Toxicity of Ingested Industrial Fluoride

    Directory of Open Access Journals (Sweden)

    Richard Sauerheber

    2013-01-01

    Full Text Available The effects of calcium ion and broad pH ranges on free fluoride ion aqueous concentrations were measured directly and computed theoretically. Solubility calculations indicate that blood fluoride concentrations that occur in lethal poisonings would decrease calcium below prevailing levels. Acute lethal poisoning and also many of the chronic effects of fluoride involve alterations in the chemical activity of calcium by the fluoride ion. Natural calcium fluoride with low solubility and toxicity from ingestion is distinct from fully soluble toxic industrial fluorides. The toxicity of fluoride is determined by environmental conditions and the positive cations present. At a pH typical of gastric juice, fluoride is largely protonated as hydrofluoric acid HF. Industrial fluoride ingested from treated water enters saliva at levels too low to affect dental caries. Blood levels during lifelong consumption can harm heart, bone, brain, and even developing teeth enamel. The widespread policy known as water fluoridation is discussed in light of these findings.

  2. Fluoride Adsorption by Pumice from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Amir Hossein Mahvi

    2012-01-01

    Full Text Available Drinking water provides many vital elements for the human body, but the presence of some dissolved elements more than permissible concentration can endanger human health. Among the dissolved elements in drinking water, fluoride is noticeable, because both the very low or very high concentrations have adverse health impacts such as dental caries. Therefore, fluoride concentration should be kept in acceptable levels. In this study Pumice was used for fluoride removal. It was found that Fluoride sorption kinetic was fitted by pseudo-second-order model. The maximum sorption capacity of Pumice was found to be 13.51 mg/g at laboratory temperature (24°C. Maximum sorption study occurred at pH= 3. Results of Isotherm showed the fluoride sorption has been well fitted with Freundlich isotherm model. This study has demonstrated that Pumice can be used as effective adsorbents for fluoride removal from aqueous solutions. The adsorbent prepared in this study was cheap and efficient in removal of fluoride than other adsorbents.

  3. Current status of fluoride volatility method development

    Energy Technology Data Exchange (ETDEWEB)

    Uhlir, J.; Marecek, M.; Skarohlid, J. [UJV - Nuclear Research Institute, Research Centre Rez, CZ-250 68 Husinec - Rez 130 (Czech Republic)

    2013-07-01

    The Fluoride Volatility Method is based on a separation process, which comes out from the specific property of uranium, neptunium and plutonium to form volatile hexafluorides whereas most of fission products (mainly lanthanides) and higher transplutonium elements (americium, curium) present in irradiated fuel form nonvolatile tri-fluorides. Fluoride Volatility Method itself is based on direct fluorination of the spent fuel, but before the fluorination step, the removal of cladding material and subsequent transformation of the fuel into a powdered form with a suitable grain size have to be done. The fluorination is made with fluorine gas in a flame fluorination reactor, where the volatile fluorides (mostly UF{sub 6}) are separated from the non-volatile ones (trivalent minor actinides and majority of fission products). The subsequent operations necessary for partitioning of volatile fluorides are the condensation and evaporation of volatile fluorides, the thermal decomposition of PuF{sub 6} and the finally distillation and sorption used for the purification of uranium product. The Fluoride Volatility Method is considered to be a promising advanced pyrochemical reprocessing technology, which can mainly be used for the reprocessing of oxide spent fuels coming from future GEN IV fast reactors.

  4. Corrosion Inhibitors for Aluminum.

    Science.gov (United States)

    Muller, Bodo

    1995-01-01

    Describes a simple and reliable test method used to investigate the corrosion-inhibiting effects of various chelating agents on aluminum pigments in aqueous alkaline media. The experiments that are presented require no complicated or expensive electronic equipment. (DDR)

  5. Advances in aluminum anodizing

    Science.gov (United States)

    Dale, K. H.

    1969-01-01

    White anodize is applied to aluminum alloy surfaces by specific surface preparation, anodizing, pigmentation, and sealing techniques. The development techniques resulted in alloys, which are used in space vehicles, with good reflectance values and excellent corrosive resistance.

  6. Determination of the stability constant of Np(V) fluoride complex using a fluoride ion selective electrode

    Energy Technology Data Exchange (ETDEWEB)

    Sawant, R.M.; Rizvi, G.H.; Chaudhuri, N.K.; Patil, S.K. (Bhabha Atomic Research Centre, Bombay (India). Radiochemistry Div.)

    1985-04-01

    Fluoride complexing of Np(V) was studied using fluoride ion selective electrode (F-ISE). Free fluoride ion concentrations in the presence of Np(V) were measured at 0.1 and 0.01M ionic strength. The data were used to calculate the stability constant of the fluoride complex of Np(V) and the values obtained are reported.

  7. CORROSION PROTECTION OF ALUMINUM

    Science.gov (United States)

    Dalrymple, R.S.; Nelson, W.B.

    1963-07-01

    Treatment of aluminum-base metal surfaces in an autoclave with an aqueous chromic acid solution of 0.5 to 3% by weight and of pH below 2 for 20 to 50 hrs at 160 to 180 deg C produces an extremely corrosion-resistant aluminum oxidechromium film on the surface. A chromic acid concentration of 1 to 2% and a pH of about 1 are preferred. (D.C.W.)

  8. A fluoride release-adsorption-release system applied to fluoride-releasing restorative materials.

    Science.gov (United States)

    Suljak, J P; Hatibovic-Kofman, S

    1996-09-01

    This investigation compared the initial fluoride release and release following refluoridation of three resin-modified glass-ionomer cements (Photac-Fil Applicap, Vitremer, and Fuji II LC) and a new polyacid-modified resin composite material (Dyract). After daily flouride release was measured for 8 days, specimens were refluoridated in 1,000-ppm solutions of fluoride ion for 10 minutes and fluoride release was measured for 5 days. Two further 5-day refluoridation-release periods were carried out. All materials released fluoride initially. Photac released the most; Dyract released the least. Initial release was greatest over the first few days. All materials released significantly more fluoride for 24 to 48 hours after refluoridation. Less fluoride was released with each successive refluoridation for the three glass-ionomer cements. The release from the Dyract compomer remained at a comparatively constant and significantly lower level following each refluoridation.

  9. A study of fluoride groundwater occurrence in Nathenje, Lilongwe, Malawi

    Science.gov (United States)

    Msonda, K. W. M.; Masamba, W. R. L.; Fabiano, E.

    A study was carried out to determine fluoride concentration in groundwaters of Nathenje area situated in Lilongwe District in the central region of Malawi. Water samples were collected from 176 boreholes and shallow wells during different months in 2001 and 2002. Samples were then analysed for fluoride by using a fluoride electrode and an ion selective meter. The results showed that fluoride concentrations for the rainy season varied from dental fluorosis in areas where the fluoride concentration was high.

  10. Topical fluoride as a cause of dental fluorosis in children

    OpenAIRE

    Wong, MCM; Lo, ECM; Glenny, AM; Tsang, BWK; Worthington, HV; Marinho, VCC

    2009-01-01

    BACKGROUND: For many years, topical use of fluorides has gained greater popularity than systemic use of fluorides. A possible adverse effect associated with the use of topical fluoride is the development of dental fluorosis due to the ingestion of excessive fluoride by young children with developing teeth. OBJECTIVES: To describe the relationship between the use of topical fluorides in young children and the risk of developing dental fluorosis. SEARCH STRATEGY: Electronic search of the Cochra...

  11. Comparison of Sampling Efficiency between Monopotassium Phosphate and Sodium Hydroxide Soaked Filter Paper for the Determination of Fluorides in the Air of Workplace%两种采样材料对工作场所空气中氟化物的采样效率

    Institute of Scientific and Technical Information of China (English)

    黄燕玲; 林琼; 陈松根; 胡勤

    2013-01-01

    [目的]比较不同采样材料对工作场所空气中氟化物的采样效率. [方法]用磷酸氢二钾的浸渍玻璃纤维滤膜和氢氧化钠的浸渍玻璃纤维滤膜作为采样材料,在同一作业岗位对空气中氟化物进行短时间采样,检测短时间接触容许浓度,滤膜以淋洗液碳酸钠-碳酸氢钠洗脱,均用离子色谱法测定. [结果]经t检验分析表明,以蒸气态、气溶胶形式存在的氟化物用磷酸氢二钾浸溃的玻璃纤维滤膜采样,其采样效率优于氢氧化钠浸渍滤膜采样方法,在0.10~1.60μg/mL范围内线性关系良好,相关系数为0.9992,检出限为0.02 μg/mL,采用高、中、低3个浓度加标回收,加标回收率为99.1%~104.7%. [结论]对两种采样材料的采样效率比较结果表明,以利用磷酸氢二钾浸渍玻璃纤维滤膜对工作场所空气中氟化物采样并用离子色谱法检测的效率更高,操作简单,重复性好,洗脱率、回收率、灵敏度均能满足工作场所空气中氟化物的检测要求.故该采样材料可推荐为工作场所空气中以气溶胶且是蒸气态为主的氟化物测定的采样材料.%[ Objective ] To compare the efficiency of different sampling materials for fluorides in the air of workplace. [ Methods ] Glass fiber membrane filters soaked in K2HPO4 and NaOH respectively were used for short time air sampling of fluorides at the same workplace with the requirement of permissible concentration-short term exposure limit (PC-STEL). After eluted with Na2CO3-NaHCO3 solution, the samples were analyzed by ion chromatography. [ Results ] The results of Mest analysis showed better sampling efficiency in K2HPO4 soaked membrane filter for fluorides in vapor phase and in aerosols. The linearity was excellent within the range of 0.10-1.60 μg/mL, with a correlation coefficient of 0.9992, and the detection limit was 0.02μg/mL. The mean spike recovery was 99.1%-104.7%. [ Conclusion ] The study findings recommend K2HPO

  12. Studies on the method for determination of fluoride concentration in rat hard tissues by neutron activation analysis using sup 20 F

    Energy Technology Data Exchange (ETDEWEB)

    Nakakura, Tadao (Nippon Dental Univ., Tokyo (Japan))

    1991-04-01

    Neutron activation analysis method (non disruptive analysis, short time period measurement) has been recognized as a high precision analysis of fluoride concentration in hard tissue. Heat neutron irradiation analysis using instrumental neutron activation analysis (INAA) method was used to investigate {sup 20}F concentration. Results were as follows. F concentration in a dried material of hard tissue using INAA method can be fixed by measuring the {sup 20}F's energy peak for 10 seconds after neutron irradiation under 1 x 10 n/cm{sup 2}center dots for 10 seconds. Non responding time that is caused by short half reduction time of {sup 20}F can be recovered enough by a revise calculation. Reproducibility of measured fluoride concentration using INAA method was well stabilized. Rat hard tissue which takes no fluoride can be determined fluoride concentration without sodium restriction. Femur fluoride concentrations using INAA method had significant correlation with conventional microdiffusion analysis method (r=0.997, regression line: Y=1.13X + 2.98). Increase of fluoride density in dentine of rat molars under growing period according to fluoride intake was 1/3 of femurs and mandibles. (author).

  13. Clinical evaluation of the intraoral fluoride releasing system in radiation-induced xerostomic subjects. Part 2: Phase I study.

    Science.gov (United States)

    Chambers, Mark S; Mellberg, James R; Keene, Harris J; Bouwsma, Otis J; Garden, Adam S; Sipos, Tibor; Fleming, Terence J

    2006-10-01

    Radiation-induced xerostomia can result in the rapid onset and progression of dental caries in head and neck cancer patients. Topically applied fluorides have been successfully used to inhibit the formation of dental caries in this population. However, because intensive daily self-application is required, compliance is an issue. The intraoral fluoride-releasing system (IFRS) containing a sodium fluoride core is a newly developed, sustained-release, passive drug delivery system that does not require patient involvement except for periodic replacement, thus reducing the effect of patient compliance on its effectiveness in dental caries prevention. Twenty-two head and neck cancer patients from U. T. M. D. Anderson Cancer Center, with radiation-induced xerostomia, were entered into a pilot study to contrast the daily home use of a 0.4% stannous fluoride-gel-containing tray (control group) to IFRS (study group) with respect to tolerability and adherence, and to obtain information on relative caries preventive efficacy. Participants were stratified on the basis of radiation exposure and randomly assigned to treatment with either IFRS or stannous fluoride gel. Patients in both groups were fitted with two IFRS retainers and also were instructed to use a 1100-ppm fluoride conventional sodium fluoride dentifrice twice daily. The study was conducted as a single-blinded, parallel-cell trial. Pre-existing carious lesions were restored prior to the beginning of the study. The efficacy variable was determined by the mean number of new or recurrent decayed surfaces. Patients were examined for caries 4, 8, 12, 24, 36, and 48 weeks after initiation of treatment. Reports of adverse reactions were based on information volunteered by patients and that were elicited during interviews. At baseline, the resting and stimulated salivary flow rates (g/5min) were significantly greater in the control group than in the study group (pIFRS groups during the study period. The rate of new or

  14. High density fluoride glass calorimeter

    Science.gov (United States)

    Xie, Q.; Scheltzbaum, J.; Akgun, U.

    2014-04-01

    The unprecedented radiation levels in current Large Hadron Collider runs, and plans to even increase the luminosity creates a need for new detector technologies to be investigated. Quartz plates to replace the plastic scintillators in current LHC calorimeters have been proposed in recent reports. Quartz based Cherenkov calorimeters can solve the radiation damage problem, however light production and transfer have proven to be challenging. This report summarizes the results from a computational study on the performance of a high-density glass calorimeter. High-density, scintillating, fluoride glass, CHG3, was used as the active material. This glass has been developed specifically for hadron collider experiments, and is known for fast response time, in addition to high light yield. Here, the details of a Geant4 model for a sampling calorimeter prototype with 20 layers, and its hadronic as well as electromagnetic performances are reported.

  15. Dental fluorosis and skeletal fluoride content as biomarkers of excess fluoride exposure in marsupials.

    Science.gov (United States)

    Death, Clare; Coulson, Graeme; Kierdorf, Uwe; Kierdorf, Horst; Morris, William K; Hufschmid, Jasmin

    2015-11-15

    Particulate and gaseous fluoride emissions contaminate vegetation near fluoride-emitting industries, potentially impacting herbivorous wildlife in neighboring areas. Dental fluorosis has been associated with consumption of fluoride-contaminated foliage by juvenile livestock and wildlife in Europe and North America. For the first time, we explored the epidemiology and comparative pathology of dental fluorosis in Australian marsupials residing near an aluminium smelter. Six species (Macropus giganteus, Macropus rufogriseus, Wallabia bicolor, Phascolarctos cinereus, Trichosurus vulpecula, Pseudocheirus peregrinus) demonstrated significantly higher bone fluoride levels in the high (n=161 individuals), compared to the low (n=67 individuals), fluoride areas (pdental fluorosis in eutherian mammals. Within the high-fluoride area, 67% of individuals across the six species showed dental enamel lesions, compared to 3% in the low-fluoride areas. Molars that erupted before weaning were significantly less likely to display pathological lesions than those developing later, and molars in the posterior portion of the dental arcade were more severely fluorotic than anterior molars in all six species. The severity of dental lesions was positively associated with increasing bone fluoride levels in all species, revealing a potential biomarker of excess fluoride exposure.

  16. Synthesis and characterization of branched yttrium hydroxide fluoride microcrystals with hierarchical tubular structure

    Institute of Scientific and Technical Information of China (English)

    TIAN Li; JIANG Wentao; SUN Qiliang; LIU Jin

    2012-01-01

    Hexagonal yttrium hydroxide fluoride microcrystals were prepared by a two-step hydrothermal route using yttrium nitrate,sodium hydroxide and sodium fluoride as raw materials to react in propanetriol solvent.The samples were characterized by powder X-ray diffraction (XRD),energy dispersive spectrum (EDS),scanning electron microscopy (SEM),transmission electron microscopy (TEM),Fourier transform infrared spectroscopy (FT-IR),thermogravimetre and differential-thermogravimetric analysis (TG-DTA),which revealed that Y(OH)2.14F0.86 microcrystals were multi-branched and that the branches of Y(OH)2.14F0.86 microcrystals were composed of hierarchical tubes.This novel multi-branched and intriguing hierarchical tubular structure of yttrium hydroxide fluoride maybe has a potential application in photoelectric crystals.The formation of branched Y(OH)2.14F0.86 microcrystals with hierarchical tubular structure were due to the substitution reaction and Oswald ripening.

  17. Alkali metal cation complexation and solvent interactions by robust chromium(III) fluoride complexes

    DEFF Research Database (Denmark)

    Birk, T.; Magnussen, M.J.; Piligkos, Stergios

    2010-01-01

    Interaction of robust chromium(III) fluoride complexes with sodium or lithium cations in solution lead to hypsochromic spectral shifts of increasing magnitude along the series: trans-[CrF2(py)(4)](+), mer-[CrF3(terpy)], and fac-[CrF3(Me(3)tacn)]. Crystalline products isolated from solution exhibit...... mu(2)-bridging by the fluoride ligands in a linear fashion between Na+-ions and chromium centres in catena-[Na(H2O)(4)(mu-F)-trans-{CrF(py)(4))](HCO3)(2) and in the dimers [Li(H2O)(n)(mu-F)-trans-{CrF(py)(4))}](2+) (n = 3, 4). The uncharged chromium complexes fac-[CrF3(Me(3)tacn)] and mer-[CrF3(terpy......)] have been synthesized from mer-[CrF3(py)(3)] and shown to precipitate sodium salts from solution, of which 3[CrF3(Me(3-)tacn)]center dot 2Na(Bph(4)).solv and 6[CrF3(terpy)]center dot 4Na(Bph(4)).solv have been crystallographically characterized. In these clusters, the neutral fluoride complexes bring...

  18. Aluminum, parathyroid hormone, and osteomalacia

    Energy Technology Data Exchange (ETDEWEB)

    Burnatowska-Hledin, M.A.; Kaiser, L.; Mayor, G.H.

    1983-01-01

    Aluminum exposure in man is unavoidable. The occurrence of dialysis dementia, vitamin D-resistant osteomalacia, and hypochromic microcytic anemia in dialysis patients underscores the potential for aluminum toxicity. Although exposure via dialysate and hyperalimentation leads to significant tissue aluminum accumulation, the ubiquitous occurrence of aluminum and the severe pathology associated with large aluminum burdens suggest that smaller exposures via the gastrointestinal tract and lungs could represent an important, though largely unrecognized, public health problem. It is clear that some aluminum absorption occurs with the ingestion of small amounts of aluminum in the diet and medicines, and even greater aluminum absorption is seen in individuals consuming large amounts of aluminum present in antacids. Aluminum absorption is enhanced in the presence of elevated circulating parathyroid hormone. In addition, elevated PTH leads to the preferential deposition of aluminum in brain and bone. Consequently, PTH is likely to be involved in the pathogenesis of toxicities in those organs. PTH excess also seems to lead to the deposition of aluminum in the parathyroid gland. The in vitro demonstration that aluminum inhibits parathyroid hormone release is consistent with the findings of a euparathyroid state in dialysis patients with aluminum related vitamin D-resistant osteomalacia. Nevertheless, it seems likely that hyperparathyroidism is at least initially involved in the pathogenesis of aluminum neurotoxicity and osteomalacia; the increases in tissue aluminum stores are followed by suppression of parathyroid hormone release, which is required for the evolution of osteomalacia. Impaired renal function is not a prerequisite for increased tissue aluminum burdens, nor for aluminum-related organ toxicity. Consequently, it is likely that these diseases will be observed in populations other than those with chronic renal disease.

  19. Caries-inhibiting effect of professional fluoride gel application in low-caries children initially aged 4.5-6.5 years.

    NARCIS (Netherlands)

    Rijkom, H.M. van; Truin, G.J.; Hof, M.A. van 't

    2004-01-01

    It was the purpose of the study to investigate the caries-reducing effect of semi-annual professional fluoride gel application in a low-caries child population initially aged 4.5-6.5 years during a 4-year follow-up period. In a double-blind randomised controlled trial (n = 773) the effect of sodium

  20. Materials processing apparatus development for fluoride glass

    Science.gov (United States)

    Smith, Guy A.; Kosten, Sue; Workman, Gary L.

    1994-01-01

    Fluoride glasses have great potential for optical fiber communications due to the high transmittance when no microcrystallites occur during drawing operations. This work has developed apparatus to test the occurrence of microcrystallites during recrystallization in reduced gravity on the KC-135. The apparatus allows fluoride glass fiber, such as ZBLAN, to be melted and recrystallized during both the low and high g portions the parabolic flight.

  1. Fluoride geochemistry of thermal waters in Yellowstone National Park: I. Aqueous fluoride speciation

    Science.gov (United States)

    Deng, Y.; Nordstrom, D.K.; Blaine, McCleskey R.

    2011-01-01

    Thermal water samples from Yellowstone National Park (YNP) have a wide range of pH (1-10), temperature, and high concentrations of fluoride (up to 50mg/l). High fluoride concentrations are found in waters with field pH higher than 6 (except those in Crater Hills) and temperatures higher than 50??C based on data from more than 750 water samples covering most thermal areas in YNP from 1975 to 2008. In this study, more than 140 water samples from YNP collected in 2006-2009 were analyzed for free-fluoride activity by ion-selective electrode (ISE) method as an independent check on the reliability of fluoride speciation calculations. The free to total fluoride concentration ratio ranged from 99% at high pH. The wide range in fluoride activity can be explained by strong complexing with H+ and Al3+ under acidic conditions and lack of complexing under basic conditions. Differences between the free-fluoride activities calculated with the WATEQ4F code and those measured by ISE were within 0.3-30% for more than 90% of samples at or above 10-6 molar, providing corroboration for chemical speciation models for a wide range of pH and chemistry of YNP thermal waters. Calculated speciation results show that free fluoride, F-, and major complexes (HF(aq)0, AlF2+, AlF2+ and AlF30) account for more than 95% of total fluoride. Occasionally, some complex species like AlF4-, FeF2+, FeF2+, MgF+ and BF2(OH)2- may comprise 1-10% when the concentrations of the appropriate components are high. According to the simulation results by PHREEQC and calculated results, the ratio of main fluoride species to total fluoride varies as a function of pH and the concentrations and ratios of F and Al. ?? 2011.

  2. Fluoride release and uptake capacities of fluoride-releasing restorative materials.

    Science.gov (United States)

    Attar, Nuray; Turgut, Melek D

    2003-01-01

    Many fluoride-releasing dental materials are being sold on the basis of their cariostatic properties. However, the amount fluoride release of these materials is still uncertain. This study investigated the fluoride release and uptake characteristics of four flowable resin composites (Heliomolar Flow, Tetric Flow, Wave, Perma Flo), one flowable compomer (Dyract flow), one conventional glass ionomer cement mixed with two different powder/liquid ratios (ChemFlex Syringeable and ChemFlex Condensable), one packable resin composite (SureFil), one ion-releasing composite (Ariston pHc) and one resin-modified glass ionomer cement (Vitremer). Seven discs (6-mm diameter and 1.5-mm height) were prepared for each material. Each disc was immersed in 3.5 ml of deionized water within a plastic vial and stored at 37 degrees C. The deionized water was changed every 24 hours and the release of fluoride was measured for 30 days. At the end of this period, the samples were recharged with 2 ml of 1.23% acidulated phosphate fluoride (APF) gel for four minutes. Then, all samples were reassessed for an additional 10 days. The fluoride release of all samples was measured with a specific fluoride electrode and an ionanalyzer. Statistical analyses were conducted using two-way repeated measure ANOVA and Duncan's multiple range tests. For all tested materials, the greatest fluoride release was observed after the first day of the study (p0.05). Ariston pHc released the highest amount of fluoride, followed by ChemFlex Syringeable, Vitremer and ChemFlex Condensable. There were statistically significant differences among these materials (p<0.05). Fluoride release of all materials were significantly increased after the first day following refluoridation and Ariston pHc released the greatest among all materials (p<0.01). At the end of two days of refluoridation, the fluoride release rate for each material dropped quickly and stabilized within three days.

  3. Well Waters Fluoride in Enugu, Nigeria

    Directory of Open Access Journals (Sweden)

    EI Ugwuja

    2012-03-01

    Full Text Available Abnormal fluoride levels in drinking water have been associated with adverse health effects. To determine the fluoride content of well waters in Enugu, southeastern Nigeria, water samples from 50 artisan wells chosen by multistage sampling procedure from the 5 zones of Enugu municipality were analyzed in duplicates for their fluoride content. The zonal mean values were 0.60, 0.70, 0.62, 0.62, and 0.63 mg/L for Abakpa Nike, Achara Layout, Obiagu/ Ogui, Trans Ekulu and Uwani, respectively (p<0.05. The mean value for the whole city was 0.63 mg/L. Although, the mean level of fluoride recorded in this study is currently within safe limits (1.5 mg/L, WHO 2011, it is important to monitor continuously the fluoride content of well waters in the municipality in view of the increasing industrial activities going on in the city and heavy reliance on well water for domestic purposes and the widespread use of consumer products containing fluoride.

  4. Analysis of fluoride concentration in solutions prepared at dispensing pharmacies

    Directory of Open Access Journals (Sweden)

    Eduardo Pizzatto

    2011-07-01

    Full Text Available Introduction: Fluoride plays an important role in oral health promotion and is considered important in dental caries prevention both in children and adults. Fluoride is widely used at high-risk conditions of caries, when the use of fluoride-containing mouthwashes is recommended, considering that fluoride itself reduces the risk of dental caries. Objective: To evaluate the fluoride concentration in solutions prepared at different dispensing pharmacies in the city of Curitiba – PR, Brazil. Material and methods: The analysis of fluoride concentration was preformed through Ion Chromatography method (DIONEX. Results: The results obtained through this analysis showed that all solutions presented fluoride concentration above that required in the dentist’s prescription, varying between 5.48% and 24.02% more fluoride, at absolute concentration. Conclusion: This finding highlights the increasing risk of fluoride acute intoxication in cases of accidental ingestion of the solution.

  5. Effect of fluoride mouth rinses on various orthodontic archwire alloys tested by modified bending test: An in vitro study

    Directory of Open Access Journals (Sweden)

    Kamna Srivastava

    2012-01-01

    Full Text Available Objective: Fluorides can cause corrosion and degradation in mechanical properties of commonly used archwires by forming hydrofluoric acid HF and causing disruption of protective titanium oxide layer. Hence, the aim of this study was to assess the change in load deflection characteristics of Ni-Ti, Cu Ni-Ti, S.S, and β-Ti wires on immersing in fluoride mouth rinses of two types- Phosflur and neutral NaF mouth rinse utilizing a modified bending test and comparing it to control. Materials and Methods: Round preformed wires were immersed in 10 ml of control and test solution (Phosflur and S-Flo mouth rinse for 1.5 hours and incubated at 37°C. Modified bending test was carried out to evaluate load-deflection characteristics of different wires using Instron. Analysis of variance (ANOVA was applied to determine if statistically significant difference exist among the mean load values obtained at various deflections in control and test solutions. Results: There was no statistically significant reduction in load deflection characteristics of Ni-Ti, copper Ni-Ti, β-Ti, and S.S wires on immersing in Phosflur mouth rinse and neutral sodium fluoride mouth rinses as compared to control at 2.5 and 1 mm of deflection in unloading phase. Conclusion: Phosflur and a neutral sodium fluoride mouth rinse did not affect the mechanical bending properties of Ni-Ti, copper Ni-Ti, B-Ti, and SS wires in in vitro conditions.

  6. Effect of fluorides (KF and NaF) on the growth of dicalcium phosphate dihydrate (DCPD) crystal

    Energy Technology Data Exchange (ETDEWEB)

    Sekar, C. [Department of Physics, Periyar University, Salem 636011, Tamilnadu (India)], E-mail: Sekar2025@gmail.com; Kanchana, P.; Nithyaselvi, R. [Department of Physics, Periyar University, Salem 636011, Tamilnadu (India); Girija, E.K. [School of Physics, Madurai Kamaraj University, Madurai 625021 (India)

    2009-05-15

    Dicalcium phosphate dihydrate (CaHPO{sub 4}.2H{sub 2}O, DCPD also known as brushite) is the major component of hard tissues like bone, teeth and a medicine for calcium supply. The effect of sodium fluoride and potassium fluoride on the crystallization of DCPD in sodium meta silicate gel has been studied at room temperature under the physiological pH (7.4). Addition of fluorides reduces the crystal size and the number of crystals grown when compared to pure system. Among the two fluorides, the KF suppresses the crystal formation more drastically than that of NaF. In both the cases, the 'Ca' content in the DCPD crystals was found to be less when compared to its pure form. The crystal morphology, elemental composition and properties of the grown crystals were analyzed using SEM-EDAX, powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermal analysis (TG-DSC)

  7. Fabrication of aluminum foam from aluminum scrap Hamza

    Directory of Open Access Journals (Sweden)

    O. A. Osman1 ,

    2015-02-01

    Full Text Available In this study the optimum parameters affecting the preparation of aluminum foam from recycled aluminum were studied, these parameters are: temperature, CaCO3 to aluminum scrap wt. ratio as foaming agent, Al2O3 to aluminum scrap wt. ratio as thickening agent, and stirring time. The results show that, the optimum parameters are the temperature ranged from 800 to 850oC, CaCO3 to aluminum scrap wt. ratio was 5%, Al2O3 to aluminum scrap wt. ratio was 3% and stirring time was 45 second with stirring speed 1200 rpm. The produced foam apparent densities ranged from 0.40-0.60 g/cm3. The microstructure of aluminum foam was examined by using SEM, EDX and XRD, the results show that, the aluminum pores were uniformly distributed along the all matrices and the cell walls covered by thin oxide film.

  8. Repair, Evaluation, Maintenance, and Rehabilitation Research Program. State-of-the-Art Procedures for Sealing Coastal Structures with Grouts and Concretes

    Science.gov (United States)

    1989-04-01

    sulfurous , boric, carbonic, and oxalic acid . Spe- cific salts include sodium bisulfate , sodium tetraborate, sodium bicarbonate, potassium-hydrogen oxalate...potassium bichromate, ferric chloride, sulfuric acid , aluminum sulfate (alum), aluminum chloride, ammonium persulfate, and copper sulfate. The bichromates... bisulfates , bicarbonates, sulfur dioxide, and sodium silico- fluoride. Sodium silicate also reacts with salts of some metals, such as 23 calcium

  9. Review paper: Role of aluminum in glass-ionomer dental cements and its biological effects.

    Science.gov (United States)

    Nicholson, John W; Czarnecka, Beata

    2009-11-01

    The role of aluminum in glass-ionomers and resin-modified glass-ionomers for dentistry is reviewed. Aluminum is included in the glass component of these materials in the form of Al(2)O(3) to confer basicity on the glass and enable the glass to take part in the acid-base setting reactions. Results of studies of these reactions by FTIR and magic-angle spinning (MAS)-NMR spectroscopy are reported and the role of aluminum is discussed in detail. Aluminum has been shown to be present in the glasses in predominantly 4-coordination, as well as 5- and 6-coordination, and during setting a proportion of this is converted to 6-coordinate species within the matrix of the cement. Despite this, mature cements may contain detectable amounts of both 4- and 5-coordinate aluminum. Aluminum has been found to be leached from glass-ionomer cements, with greater amounts being released under acidic conditions. It may be associated with fluoride, with which it is known to complex strongly. Aluminum that enters the body via the gastro-intestinal tract is mainly excreted, and only about 1% ingested aluminum crosses the gut wall. Calculation shows that, if a glass-ionomer filling dissolved completely over 5 years, it would add only an extra 0.5% of the recommended maximum intake of aluminum to an adult patient. This leads to the conclusion that the release of aluminum from either type of glass-ionomer cement in the mouth poses a negligible health hazard.

  10. Fluoride concentration in plaque in adolescents after topical application of different fluoride varnishes.

    Science.gov (United States)

    Sköld-Larsson, K; Modéer, T; Twetman, S

    2000-03-01

    The aim of the study was to measure the fluoride (F) concentration in plaque after a single topical application of different fluoride varnishes with contrasting levels of F. Thirty adolescents (12-17 years) with fixed orthodontic appliances were randomly assigned to one of three groups: Bifluoride (6% F), Duraphat (2.23% F) and Fluor Protector (0.1% F). The varnishes were applied after professional cleaning in one upper quadrant, leaving the opposite quadrant untreated according to the split-mouth technique. Pooled plaque samples from each quadrant were collected at baseline and 3 days, 7 days and 30 days after the varnish treatment, and fluoride was analysed by microdiffusion. All fluoride varnishes increased the fluoride concentration in plaque compared with baseline, and the mean values varied between 23 and 138 ng F/mg after 3 days, depending on varnish F concentration. Compared with the control quadrant, statistically significant elevations were recorded for Bifluoride after 3 days and 7 days and Duraphat after 3 days, while no significant differences were revealed in the Fluor Protector group. The fluoride concentration in plaque was back to baseline levels for all participants in the Duraphat group after 7 days, while some individuals in the Bifluoride and Fluor Protector groups still registered slightly increased levels after 30 days. The results suggest that fluoride varnish treatments resulted in elevated fluoride levels in plaque adjacent to fixed orthodontic appliances for a period of up to 1 week, although different patterns was disclosed for the various brands.

  11. Plaque formation and lactic acid production after use of amine fluoride/stannous fluoride mouthrinse

    NARCIS (Netherlands)

    Gerardu, V.A.M.; Buijs, M.; Loveren, C. van; Cate, J.M. ten

    2007-01-01

    The aim of this study was lo determine the effects of 3 wk of daily rinsing with amine fluoride/stannous fluoride (AmF/SnF2) mouthrinse on plaque formation at buccal and interproximal sites, and on the acid production in plaque. in a randomized clinical trial with 30 participants. The amount of plaq

  12. Ecophysiological, anatomical and ultrastructural characteristics of Vitex polygama Cham. (Verbenaceae submitted to different concentrations of fluoride

    Directory of Open Access Journals (Sweden)

    Zélia Terezinha Teixeira Rossi

    2016-12-01

    Full Text Available Fluorides released during the manufacture of aluminum, fertilizers, glass and ceramics are considered to be highly toxic to plants, causing damages in relatively small concentrations. This study aimed to evaluate fluoride (F accumulation and its effects on Vitex polygama Cham. (Verbenaceae exposed to simulated rain containing potassium fluoride in concentrations of 5, 10, 15 and 20 mg L-1. Vitex polygama presented no visual symptoms of foliar injury and accumulated a relatively small amount of F-, significant only for the treatments with higher concentrations of the pollutant.  F- promoted an increase in non-photochemical quenching (qN and in the coefficient due to non-photochemical extinction (NPQ, which indicates higher dissipation of radiant energy in the heat form. Damages in the chloroplast structure, in cellular membranes and in epicuticular waxes, besides cytoplasm granulation and irregularities in the epidermal cell walls were also detected in plants exposed to the pollutant. The results show a considerable resistance of Vitex polygama to F and reinforce the prognostic value of physiological, anatomical and ultrastructural analysis in the detection of damages caused by the pollutant in the leaf structure of this species.

  13. Cancer incidence and mortality in workers exposed to fluoride

    DEFF Research Database (Denmark)

    Grandjean, P; Olsen, J H; Jensen, O M;

    1992-01-01

    Although a recent bioassay showed increased frequency of bone cancer in rats with high oral intake of fluoride, the data are reported as equivocal evidence of carcinogenicity. In humans, occupational fluoride exposure may cause skeletal fluorosis, and our earlier follow-up of fluoride-exposed wor......Although a recent bioassay showed increased frequency of bone cancer in rats with high oral intake of fluoride, the data are reported as equivocal evidence of carcinogenicity. In humans, occupational fluoride exposure may cause skeletal fluorosis, and our earlier follow-up of fluoride...

  14. Removal of phosphorus, fluoride and metals from a gypsum mining leachate using steel slag filters.

    Science.gov (United States)

    Claveau-Mallet, Dominique; Wallace, Scott; Comeau, Yves

    2013-03-15

    The objective of this work was to evaluate the capacity of steel slag filters to treat a gypsum mining leachate containing 11-107 mg P/L ortho-phosphates, 9-37 mg/L fluoride, 0.24-0.83 mg/L manganese, 0.20-3.3 zinc and 1.7-8.2 mg/L aluminum. Column tests fed with reconstituted leachates were conducted for 145-222 days and sampled twice a week. Two types of electric arc furnace (EAF) slags and three filter sequences were tested. The voids hydraulic retention time (HRT(v)) of columns ranged between 4.3 and 19.2 h. Precipitates of contaminants present in columns were sampled and analyzed with X-ray diffraction at the end of tests. The best removal efficiencies over a period of 179 days were obtained with sequential filters that were composed of Fort Smith EAF slag operated at a total HRT(v) of 34 h which removed 99.9% of phosphorus, 85.3% of fluoride, 98.0% of manganese and 99.3% of zinc. Mean concentration at this system's effluent was 0.04 mg P/L ortho-phosphates, 4 mg/L fluoride, 0.02 mg/L manganese, 0.02 zinc and 0.5 mg/L aluminum. Thus, slag filters are promising passive and economical systems for the remediation of mining effluents. Phosphorus was removed by the formation of apatite (hydroxyapatite, Ca(5)(PO(4))(3)OH or fluoroapatite, Ca(5)(PO(4))(3)F) as confirmed by visual and X-ray diffraction analyses. The growth rate of apatite was favored by a high phosphorus concentration. Calcite crystals were present in columns and appeared to be competing for calcium and volume needed for apatite formation. The calcite crystal growth rate was higher than that of apatite crystals. Fluoride was removed by precipitation of fluoroapatite and its removal was favored by a high ratio of phosphorus to fluoride in the wastewater.

  15. Bifluoride ([HF2](-)) formation at the fluoridated aluminium hydroxide/water interface.

    Science.gov (United States)

    Shimizu, Kenichi; Driver, Gordon W; Lucas, Marie; Sparrman, Tobias; Shchukarev, Andrey; Boily, Jean-François

    2016-05-31

    This study uncovers bifluoride-type (difluorohydrogenate(i); [HF2](-)) species formed at mineral/water interfaces. Bifluoride forms at [triple bond, length as m-dash]Al-F surface sites resulting from the partial fluoridation of gibbsite (γ-Al(OH3)) and bayerite (α-Al(OH3)) particles exposed to aqueous solutions of 50 mM NaF. Fluoride removal from these solutions is proton-promoted and results in a strongly self-buffered suspensions at circumneutral pH, proceeds at a F : H consumption ratio of 2 : 1, and with recorded losses of up to 17 mM fluoride (58 F nm(-2)). These loadings exceed crystallographic site densities by a factor of 3-4, yet the reactions have no resolvable impact on particle size, shape and mineralogy. X-ray photoelectron spectroscopy (XPS) of frozen (-155 °C) wet mineral pastes revealed coexisting surface F(-) and HF(0) species. Electron energy loss features pointed to multilayer distribution of these species at the mineral/water interface. XPS also uncovered a distinct form of Na(+) involved in binding fluoride-bearing species. XPS and solid state magic angle spinning (19)F nuclear magnetic resonance measurements showed that these fluoride species were highly comparable to a sodium-bifluoride (NaHF2) reference. First layer surface species are represented as [triple bond, length as m-dash]Al-F-H-F-Al[triple bond, length as m-dash] and [triple bond, length as m-dash]Al-F-Na-F-Al[triple bond, length as m-dash], and may form multi-layered species into the mineral/water interface. These results consequently point to a potentially overlooked inorganic fluorine species in a technologically relevant mineral/water interfacial systems.

  16. Influence of the method of fluoride administration on toxicity and fluoride concentrations in Japanese quail

    Science.gov (United States)

    Fleming, W.J.; Schuler, C.A.

    1988-01-01

    Young Japanese quail (Coturnix japonica) were administered NaF for 16 d either in their diet or by esophageal intubation. Based on the total fluoride ion (Emg F-) intake over the l6-d experimental period, fluoride administered by intubation was at least six times more toxic than that fed in the diet. Dietary concentrations of 1,000 ppm F- (Emg F- for 16 d = approx. 144) produced no mortality, whereas intubated doses produced 73% or greater mortality in all groups administered 54 mg F- /kg/d or more (Emg F- for 16 d _ approx. 23 mg). GraphIc companson of the regression of log F- ppm in femurs/mg F- intake showed that fluoride levels in the femurs of quail administered fluoride by intubation were higher than in those administered fluoride in the diet.

  17. Copper, aluminum, iron and calcium inhibit human acetylcholinesterase in vitro.

    Science.gov (United States)

    Pohanka, Miroslav

    2014-01-01

    Acetylcholinesterase (AChE) is an important part of cholinergic nerves where it participates in termination of neurotransmission. AChE can be inhibited by e.g. some Alzheimer disease drugs, nerve agents, and secondary metabolites. In this work, metal salts aluminum chloride, calcium chloride, cupric chloride, ferric chloride, potassium chloride, magnesium chloride and sodium chloride were tested for their ability to inhibit AChE. Standard Ellman assay based on human recombinant AChE was done and inhibition was measured using Dixon plot. No inhibition was proved for sodium, potassium and magnesium ions. However, aluminum, cupric, ferric and calcium ions were able to inhibit AChE via noncompetitive mechanism of inhibition. Though the inhibition is much weaker when compared to e.g. drugs with noncompetitive mechanism of action, biological relevance of the findings can be anticipated.

  18. On the crucial influence of some supporting electrolytes during electrocoagulation in the presence of aluminum electrodes

    OpenAIRE

    Trompette, Jean-Luc; Vergnes, Hugues

    2009-01-01

    The influence of some supporting electrolytes on aluminum electrode oxidation and pH variation during electrocoagulation of an unskimmed milk sample and a cutting oil emulsion has been investigated. Among the electrolytes studied, sulfate anions were found to be quite harmful both for electrical consumption and electrocoagulation efficiency. At the opposite, chloride and ammonium ionswere particularly benefic respectively for aluminum corrosion and pH regulation, whereas sodium cations were o...

  19. Electrically conductive anodized aluminum coatings

    Science.gov (United States)

    Alwitt, Robert S. (Inventor); Liu, Yanming (Inventor)

    2001-01-01

    A process for producing anodized aluminum with enhanced electrical conductivity, comprising anodic oxidation of aluminum alloy substrate, electrolytic deposition of a small amount of metal into the pores of the anodized aluminum, and electrolytic anodic deposition of an electrically conductive oxide, including manganese dioxide, into the pores containing the metal deposit; and the product produced by the process.

  20. China’s Aluminum Resources

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    <正> The aluminum industry makes one of the keyindustries in China’s industrial and agriculturalmodernization and features a high degree ofrelevance with all industries.Of all the 124existing industries in China,113 use aluminum,representing an industrial relevance rate of91%.The consumption of aluminum is also ofhigh relevance with China’s GDP.

  1. Aluminum for Plasmonics

    Science.gov (United States)

    2014-01-01

    in plasmon-enhanced light harvesting,14 photocatalysis ,511 surface- enhanced spectroscopies,1216 optics-based sensing,1722 nonlinear optics,2326...optical response of Al nanoparticles has appeared inconsistent relative to calculated spectra, even forwell-characterized geometries. Some studies have...model- ing their optical response. These results pro- vide a method for estimating the metallic purity of aluminum nanoparticles directly from their

  2. Thermodynamic data-base for metal fluorides

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Jae Hyung; Lee, Byung Gik; Kang, Young Ho and others

    2001-05-01

    This study is aimed at collecting useful data of thermodynamic properties of various metal fluorides. Many thermodynamic data for metal fluorides are needed for the effective development, but no report of data-base was published. Accordingly, the objective of this report is to rearrange systematically the existing thermodynamic data based on metal fluorides and is to use it as basic data for the development of pyrochemical process. The physicochemical properties of various metal fluorides and metals were collected from literature and such existing data base as HSC code, TAPP code, FACT code, JANAF table, NEA data-base, CRC handbook. As major contents of the thermodynamic data-base, the physicochemical properties such as formation energy, viscosity, density, vapor pressure, etc. were collected. Especially, some phase diagrams of eutectic molten fluorides are plotted and thermodynamic data of liquid metals are also compiled. In the future, the technical report is to be used as basic data for the development of the pyrochemical process which is being carried out as a long-term nuclear R and D project.

  3. Chemically modified field effect transistors with nitrite or fluoride selectivity

    NARCIS (Netherlands)

    Antonisse, Martijn M.G.; Snellink-Ruël, Bianca H.M.; Engbersen, Johan F.J.; Reinhoudt, David N.

    1998-01-01

    Polysiloxanes with different types of polar substituents are excellent membrane materials for nitrite and fluoride selective chemically modified field effect transistors (CHEMFETs). Nitrite selectivity has been introduced by incorporation of a cobalt porphyrin into the membrane; fluoride selectivity

  4. A biomimetic tactile sensing system based on polyvinylidene fluoride film

    Science.gov (United States)

    Xin, Yi; Tian, Hongying; Guo, Chao; Li, Xiang; Sun, Hongshuai; Wang, Peiyuan; Qian, Chenghui; Wang, Shuhong; Wang, Cheng

    2016-02-01

    Polyvinylidene fluoride (PVDF) film has been widely investigated as a sensing material due to its outstanding properties such as biocompatibility, high thermal stability, good chemical resistance, high piezo-, pyro- and ferro-electric properties. This paper reports on the design, test, and analysis of a biomimetic tactile sensor based on PVDF film. This sensor consists of a PVDF film with aluminum electrodes, a pair of insulating layers, and a "handprint" friction layer with a copper foil. It is designed for easy fabrication and high reliability in outputting signals. In bionics, the fingerprint of the glabrous skin plays an important role during object handling. Therefore, in order to enhance friction and to provide better manipulation, the ridges of the fingertips were introduced into the design of the proposed tactile sensor. And, a basic experimental study on the selection of the high sensitivity fingerprint type for the biomimetic sensor was performed. In addition, we proposed a texture distinguish experiment to verify the sensor sensitivity. The experiment's results show that the novel biomimetic sensor is effective in discriminating object surface characteristics. Furthermore, an efficient visual application program (LabVIEW) and a quantitative evaluation method were proposed for the verification of the biomimetic sensor. The proposed tactile sensor shows great potential for contact force and slip measurements.

  5. Electroless Growth of Aluminum Dendrites in NaCl-AlCl3 Melts

    DEFF Research Database (Denmark)

    Li, Qingfeng; Hjuler, H.A.; Berg, Rolf W.

    1989-01-01

    The spontaneous growth of aluminum dendrites after deposition was observed and examined in sodium chloride-aluminumchloride melts. The concentration gradient of AlCl3 in the vicinity of the cathode surface resulting from electrolysisconstitutes a type of concentration cell with aluminum dendrites...... as electrodes. The short-circuit discharge of thecell is found to be the driving force for the growth of aluminum dendrites. Such a concentration gradient is proposed to beone of the causes for dendrite formation in the case of metal deposition....

  6. A simple and colorimetric fluoride receptor and its fluoride-responsive organogel

    Energy Technology Data Exchange (ETDEWEB)

    Yu Xudong, E-mail: 081022009@fudan.edu.cn [College of Science, Hebei University of Science and Technology, Yuhua Road 70, Shijiazhuang 050080 (China); Li Yajuan [College of Science, Hebei University of Science and Technology, Yuhua Road 70, Shijiazhuang 050080 (China); Yin Yaobing; Yu Decai [College of Science, Hebei University of Engineering, 199 South street of Guangming, Handan 056038 (China)

    2012-08-01

    In this paper, a new p-nitrophenylhydrozine-based anion receptor 1 containing cholesterol group had been designed and synthesized. It could selectively recognize fluoride among different anions tested with color changes from pale yellow to red for visual detection. Simultaneously, it could gel in cyclohexane, and the gel was also fluoride-responsive. When treated with TBAF (tetra-n-butylammonium fluoride), the gel could undergo gel-sol transition accompanied by color, morphology and surface changes. The binding mechanism had been investigated by UV-vis and {sup 1}HNMR (proton nuclear magnetic resonance spectra) titrations. From SEM (scanning electron microscope), SAXS (small-angle X-ray scattering), IR (Infrared Spectroscopy) and CA (contact angle) experiments, it was indicated that the addition of F{sup -} could destroy the molecule assembly of host 1 in the gel state, thus resulting in the gel-to-sol transition due to the binding site competition effect. To the best of our knowledge, this was the simplest fluoride-responsive organogel with high selectivity. Highlights: Black-Right-Pointing-Pointer A novel kind receptor for selective recognition of fluoride had been designed. Black-Right-Pointing-Pointer Its organogel was also fluoride-responsive. Black-Right-Pointing-Pointer This is the simplest fluoride-responsive organogel with high selectivity.

  7. Estimated fluoride doses from toothpastes should be based on total soluble fluoride.

    Science.gov (United States)

    Oliveira, Maria José L; Martins, Carolina C; Paiva, Saul M; Tenuta, Livia M A; Cury, Jaime A

    2013-11-01

    The fluoride dose ingested by young children may be overestimated if based on levels of total fluoride (TF) rather than levels of bioavailable fluoride (total soluble fluoride-TSF) in toothpaste. The aim of the present study was to compare doses of fluoride intake based on TF and TSF. Fluoride intake in 158 Brazilian children aged three and four years was determined after tooth brushing with their usual toothpaste (either family toothpaste (n = 80) or children's toothpaste (n = 78)). The estimated dose (mg F/day/Kg of body weight) of TF or TSF ingested was calculated from the chemical analysis of the toothpastes. Although the ingested dose of TF from the family toothpastes was higher than that from the children's toothpastes (0.074 ± 0.007 and 0.039 ± 0.003 mg F/day/Kg, respectively; p toothpaste was found regarding the ingested dose based on TSF (0.039 ± 0.005 and 0.039 ± 0.005 mg F/day/Kg, respectively; p > 0.05). The fluoride dose ingested by children from toothpastes may be overestimated if based on the TF of the product. This finding suggests that the ingested dose should be calculated based on TSF. Dose of TSF ingested by children is similar whether family or children's toothpaste is used.

  8. Histochemical pattern of gastrocnemius muscle in fluoride toxicity syndrome

    Institute of Scientific and Technical Information of China (English)

    Shashi A; Bhushan B; Bhardwaj M

    2010-01-01

    Objective:To evaluate the effect of sodium fluoride (NaF) on cytochemical distribution of proteins, DNA, and RNA in the gastrocnemius muscle of rat in experimental fluorosis.Methods:Young Sprague Dawley albino rats were administered with NaF at 30, 45, and 75 mg/kg bw/day subcutaneously for 15 and 30 days, respectively. The control animals were given the vehicle (1cc deionized double distilled water/kg bw/day).Results: In the first phase of 15 days experimentation, the gastrocnemius muscle of rats intoxicated with NaF at 30, 45, and 75 mg /kg bw/ day showed decline in proteins includingαamino acids as compared to control. In the second phase of 30 days experimentation, the muscle fibers of rat showed elevation in sarcolemmal and sarcoplasmic proteins in 30 mg NaF dose group, and angulated fibers exhibited increase in sarcolemmal proteins in 45 mg NaF group. The marginal regions of angular and rim fibers showed deeply stained rings of sarcoplasmic proteins whereas the split fibers were faintly stained in rats treated with NaF at 75 mg/kg bw/day for 30 days. In rats treated with NaF at 30 mg/kg bw/day for 15 days, the hypertrophied peripheral muscle fibers contained more DNA, however the atrophied fibers had more RNA. In 45 mg NaF group, RNA was located in sarcolemmal regions, while DNA content decreased as compared to control. In 75 mg NaF group, the muscle fibers had dark and light staining regions of DNA and RNA. In the 30 days of experimentation, the DNA level decreased whereas RNA content increased in the gastrocnemius muscle fibers of the rat treated with NaF at 30 mg/kg bw/day. In treatment group with NaF at 45 mg/kg bw/day, the RNA content slightly declined in comparison to control, in all treatments for 15 days as well as in treatment group with NaF at 30 mg/kg bw/day for 30 days whereas the amount of DNA slightly increased as compared to treatment group with NaF at 75 mg/kg bw/day for 15 days. The highest dose group revealed elevated amount of RNA whereas

  9. The effects of fluoride on testicular cell cycle and cell apoptosis of male rats

    Institute of Scientific and Technical Information of China (English)

    张筱文

    2014-01-01

    Objective To observe the effects of fluoride on testicular cell cycle and cell apoptosis of male rats.Methods Thirty-two healthy male Wistar rats,weighting 150-180 g,were randomly divided into 4 groups by body weight using random number table,normal sodium(control),the low-dose,medium-dose and high-dose groups(100,200,300 mg·kg-1·d-1Na F,respectively)by intragastric administration for 90 days,and bodyweight

  10. Vitrification of strontium-90 fluoride

    Energy Technology Data Exchange (ETDEWEB)

    Strachan, D.M.; Schulz, W.W.

    1977-04-01

    At Hanford, strontium-90 is removed from high-level nuclear fuel reprocessing waste and converted to strontium-90 fluoride. This /sup 90/SrF/sub 2/ is doubly encapsulated in high-integrity containers which are placed under water in monitored storage pools. Conversion of /sup 90/SrF/sub 2/ to a more immobile compound may be necessary and/or desirable as part of the overall plan for the long-term management of Hanford Defense Wastes. Glasses containing up to 40 mass percent SrF/sub 2/ and having leach rates in the range 1 x 10/sup -8/ to 1 x 10/sup -5/ gram Sr/(m/sup 2/ . s) (1 x 10/sup -7/ to 1 x 10/sup -4/ g Sr/cm/sup 2/ . day)) have now been prepared. From 0.2 to 5 percent of the fluorine is volatilized during the melting of the glass batch at temperatures up to 1500/sup 0/K. At present, the heat generation limit for commercial glasses stored at a nuclear waste repository is 5 kW per canister. All glasses described here would exceed that limit by more than a factor of five. The stored /sup 90/SrF/sub 2/ may be treated separately from the bulk of Hanford waste, in which case it would be diluted to an acceptable power level with inert chemicals in the glass batch. Another option is to blend the /sup 90/SrF/sub 2/ with the bulk of the other Hanford wastes when those wastes are converted to some immobile form.

  11. Carbide Coatings for Nickel Alloys, Graphite and Carbon/Carbon Composites to be used in Fluoride Salt Valves

    Energy Technology Data Exchange (ETDEWEB)

    Nagle, Denis [Johns Hopkins Univ., Baltimore, MD (United States); Zhang, Dajie [Johns Hopkins Univ., Baltimore, MD (United States)

    2015-10-22

    The focus of this research was concerned with developing materials technology that supports the evolution of Generation IV Advanced High Temperature Reactor (AHTR) concepts. Specifically, we investigate refractory carbide coatings for 1) nickel alloys, and 2) commercial carbon-carbon composites (CCCs). Numerous compelling reasons have driven us to focus on carbon and carbide materials. First, unlike metals, the strength and modulus of CCCs increase with rising temperature. Secondly, graphite and carbon composites have been proven effective for resisting highly corrosive fluoride melts such as molten cryolite [Na₃AlF₆] at ~1000°C in aluminum reduction cells. Thirdly, graphite and carbide materials exhibit extraordinary radiation damage tolerance and stability up to 2000°C. Finally, carbides are thermodynamically more stable in liquid fluoride salt than the corresponding metals (i.e. Cr and Zr) found in nickel based alloys.

  12. Influence of fluoridation on the strength of superplastic Zn-21Al-2Cu alloy deformed in a saline medium

    Energy Technology Data Exchange (ETDEWEB)

    Elizalde-Torres, J.; Torres-Villasenor, G. [UNAM, Mexico Distrito Federal (Mexico); Sandoval-Jimenez, A. [Instituto Nacional de Investigaciones Nucleares, Mexico Distrito Federal (Mexico)

    1999-04-09

    The interest in Zi-Al-Cu alloys has intensified in recent years because they possess the highest known yield strengths among the entire series of Zn-Al superplastic alloys. The superplastic materials are generally fine-grained materials and the deformation is associated with the grain boundary processes. Because of this, the superplastic alloys are exposed to a potential danger of intergranular stress corrosion cracking under susceptible service conditions. Consequently, the study of enhancing the strength and increasing the corrosion resistance of the material at room temperature is an important research area. Fluorine passivation technology of metal surfaces (fluoridation) has been proved to be very effective in the protection of several metals such as austenitic stainless steel and aluminum. In the present investigation the superplastic Zn-Al-Cu alloy has been studied to evaluate the effects of fluoridation and the stress corrosion damage.

  13. 21 CFR 177.2510 - Polyvinylidene fluoride resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyvinylidene fluoride resins. 177.2510 Section... as Components of Articles Intended for Repeated Use § 177.2510 Polyvinylidene fluoride resins. Polyvinylidene fluoride resins may be safely used as articles or components of articles intended for repeated...

  14. 21 CFR 175.270 - Poly(vinyl fluoride) resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Poly(vinyl fluoride) resins. 175.270 Section 175... Substances for Use as Components of Coatings § 175.270 Poly(vinyl fluoride) resins. Poly(vinyl fluoride) resins identified in this section may be safely used as components of food-contact coatings...

  15. Health effects of fluoride pollution caused by coal burning

    Energy Technology Data Exchange (ETDEWEB)

    Ando, M.; Tadano, M.; Yamamoto, S.; Tamura, K.; Chen, X. [Regional Environment Division, National Institute for Environmental Studies, Tsukuba, 305-0083 Ibaraki (Japan); Asanuma, S. [Japan Institute of Rural Medicine, Usuda, Nagano (Japan); Watanabe, T. [Saku Central Hospital, Usuda, Nagano (Japan); Kondo, T. [Matsumoto Dental College, Shiojiri, Nagano (Japan); Sakurai, S. [Otsuma Women' s University, Tama, Tokyo (Japan); Ji, R.; Liang, C.; Cao, S. [Institute of Environmental Health and Engineering, Beijing (China); Hong, Z. [Shanxi Maternity and Children' s Hospital, Taiyuan (China)

    2001-04-23

    Recently a huge amount of fluoride in coal has been released into indoor environments by the combustion of coal and fluoride pollution seems to be increasing in some rural areas in China. Combustion of coal and coal bricks is the primary source of gaseous and aerosol fluoride and these forms of fluoride can easily enter exposed food products and the human respiratory tract. Major human fluoride exposure was caused by consumption of fluoride contaminated food, such as corn, chilies and potatoes. For each diagnostic syndrome of dental fluorosis, a log-normal distribution was observed on the logarithm of urinary fluoride concentration in students in China. Urinary fluoride content was found to be a primary health indicator of the prevalence of dental fluorosis in the community. In the fluorosis areas, osteosclerosis in skeletal fluorosis patients was observed with a high prevalence. A biochemical marker of bone resorption, urinary deoxypyridinoline content was much higher in residents in China than in residents in Japan. It was suggested that bone resorption was stimulated to a greater extent in residents in China and fluoride may stimulate both bone resorption and bone formation. Renal function especially glomerular filtration rate was very sensitive to fluoride exposure. Inorganic phosphate concentrations in urine were significantly lower in the residents in fluorosis areas in China than in non-fluorosis area in China and Japan. Since airborne fluoride from the combustion of coal pollutes extensively both the living environment and food, it is necessary to reduce fluoride pollution caused by coal burning.

  16. Synthesis of reagents for fluoride technologies

    Institute of Scientific and Technical Information of China (English)

    Gordienko; P.; S.; Kolzunov; V.; A.; Dostovalov; V.; A.; Kaidalova; T.; A.

    2005-01-01

    Growing demand for fluorinating reagents to be used in rare-metal industry has stimulated conducting research in the field of production for these reagents. That is why the fluorinating reagents production has recently formed an independent segment of industry. Main industrial fluorinating reagents include hydrofluoric acid, anhydrous hydrogen fluoride, technical ammonium hydrodifluoride, fluorosilicic acid and its salts. To produce technical etching acid, fluor-spar with calcium fluoride content at least 92% is used in most cases. To produce anhydrous hydrogen fluoride, fluor-spar with calcium fluoride content 96 %-97 % is necessary. The fluorine-containing raw materials refinement from silica by means of flotation makes the fluorinating reagents production substantially more expensive. In this work we have attempted to process unconcentrated raw materials by fluorine removal in the form of volatile silicon tetrafluoride. In this process silicon tetrafluoride was recovered by liquid ammonia with subsequent hydrolysis of the formed ammonia hexafluorosilicate. Hydrolysis occurred according to the reaction:(NH4)2 SiF6 + 4NH3 + 2 H2O= 6NH4F+ SiO2 The products of the ammonia hexafluorosilicate hydrolysis included ammonia fluoride and amorphous silica gel ("white soot") as by-product. This "white soot" was of high purity-with main component content 99.95% and total admixture content 0.05%. Silica gel is a superfine material with specific surface of 267.6 m2/g and is recommended as filler in the production of rubber, plastics and for other applications.Ammonia fluoride was transformed into ammonia hydrodifluoride (main processing product) according to the reaction:2NH4F→NH3+NH4 HF2 It was stated that the NH4F: NH4 HF2 ratio depends on boiling point temperature-with its increase the ammonia hydrofluoride concentration in solution increases as well.

  17. Enhanced fluoride sorption by mechanochemically activated kaolinites.

    Science.gov (United States)

    Meenakshi, S; Sundaram, C Sairam; Sukumar, Rugmini

    2008-05-01

    Kaolinite clay obtained from the mines was processed and studied for its fluoride sorption capacity. The surface area of the clay mineral was increased from 15.11 m(2)/g (raw) to 32.43 m(2)/g (activated) by mechanochemical activation. Batch adsorption studies were conducted to optimize various equilibrating conditions like the effect of contact time, dosage, pH for both raw and micronized kaolinites (RK and MK). The effect of other interfering anions on the defluoridation capacity (DC) of the sorbents was studied. Sorption of fluoride by the sorbents was observed over a wide pH range of 3-11. The studies revealed there is an enhanced fluoride sorption on MK. FTIR and XRD were used for the characterization of the sorbent. The surface morphology of the clay material was observed using SEM. The adsorption of fluoride was studied at three different temperatures, viz., 303, 313 and 323 K. The sorption data obtained at optimized conditions were subjected to Freundlich and Langmuir isotherms. Sorption intensity (1/n) (0.770-0.810) has been evaluated using Freundlich isotherm, whereas the values of sorption capacity Q(0) (0.609, 0.714 and 0.782 mg/g) and binding energy b (0.158, 0.145 and 0.133 L/mg) at three different temperatures have been estimated using Langmuir isotherm. Adsorption process was found to be controlled by both Freundlich and Langmuir isotherms. Thermodynamic studies revealed that the sorption of fluoride on MK is endothermic and a spontaneous process. The kinetic studies indicate that the sorption of fluoride on MK follows pseudo-first-order and intraparticle diffusion models.

  18. Enhanced fluoride sorption by mechanochemically activated kaolinites

    Energy Technology Data Exchange (ETDEWEB)

    Meenakshi, S. [Department of Chemistry, Gandhigram Rural University, Gandhigram 624302, Tamilnadu (India)], E-mail: drs_meena@rediffmail.com; Sundaram, C. Sairam [Department of Science and Humanities, Karaikal Polytechnic College, Karaikal 609609, Puducherry (India); Sukumar, Rugmini [Chemical Sciences and Technologies, Regional Research Laboratory, Trivandrum 695019, Kerala (India)

    2008-05-01

    Kaolinite clay obtained from the mines was processed and studied for its fluoride sorption capacity. The surface area of the clay mineral was increased from 15.11 m{sup 2}/g (raw) to 32.43 m{sup 2}/g (activated) by mechanochemical activation. Batch adsorption studies were conducted to optimize various equilibrating conditions like the effect of contact time, dosage, pH for both raw and micronized kaolinites (RK and MK). The effect of other interfering anions on the defluoridation capacity (DC) of the sorbents was studied. Sorption of fluoride by the sorbents was observed over a wide pH range of 3-11. The studies revealed there is an enhanced fluoride sorption on MK. FTIR and XRD were used for the characterization of the sorbent. The surface morphology of the clay material was observed using SEM. The adsorption of fluoride was studied at three different temperatures, viz., 303, 313 and 323 K. The sorption data obtained at optimized conditions were subjected to Freundlich and Langmuir isotherms. Sorption intensity (1/n) (0.770-0.810) has been evaluated using Freundlich isotherm, whereas the values of sorption capacity Q{sup 0} (0.609, 0.714 and 0.782 mg/g) and binding energy b (0.158, 0.145 and 0.133 L/mg) at three different temperatures have been estimated using Langmuir isotherm. Adsorption process was found to be controlled by both Freundlich and Langmuir isotherms. Thermodynamic studies revealed that the sorption of fluoride on MK is endothermic and a spontaneous process. The kinetic studies indicate that the sorption of fluoride on MK follows pseudo-first-order and intraparticle diffusion models.

  19. DNA damage, apoptosis and cell cycle changes induced by fluoride in rat oral mucosal cells and hepatocytes

    Institute of Scientific and Technical Information of China (English)

    Ling-Fei He; Jian-Gang Chen

    2006-01-01

    AIM: To study the effect of fluoride on oxidativestress,DNA damage and apoptosis as well as cell cycle of rat oral mucosal cells and hepatocytes.METHODS: Ten male SD rats weighing 80~120 g were randomly divided into control group and fluoride group,5 animals each group. The animals in fluoride group had free access to deionized water containing 150 mg/L sodium fluoride (NaF). The animals in control group were given distilled water. Four weeks later, the animals were killed. Reactive oxygen species (ROS) in oral mucosa and liver were measured by Fenton reaction, lipid peroxidation product, malondialdehyde (MDA), was detected by thiobarbituric acid (TBA) reaction, reduced glutathione (GSH) was assayed by dithionitrobenzoic acid (DTNB)reaction. DNA damage in oral mucosal cells and hepatocytes was determined by single cell gel (SCG) electrophoresis or comet assay. Apoptosis and cell cycle in oral mucosal cells and hepatocytes were detected by flow cytometry.RESULTS: The contents of ROS and MDA in oral mucosa and liver tissue of fluoride group were significantly higher than those of control group (P<0.01), but the level of GSH was markedly decreased (P<0.01). The contents of ROS, MDA and GSH were (134.73±12.63) U/mg protein,(1.48±0.13) mmol/mg protein and (76.38±6.71) mmol/mg protein in oral mucosa respectively, and (143.45±11.76) U/mg protein, (1.44±0.12) mmol/mg protein and (78.83±7.72) mmol/mg protein in liver tissue respectively. The DNA damage rate in fluoride group was 50.20%in oral mucosal cells and 44.80% in hepatocytes, higher than those in the control group (P<0.01). The apoptosis rate in oral mucosal cells was (13.63±1.81) % in fluoride group, and (12.76±1.67) % in hepatocytes,higher than those in control group. Excess fluoride could differently lower the number of oral mucosal cells and hepatocytes at G0/G1 and S G2/M phases (P<0.05).CONCLUSION: Excess fluoride can induce oxidative stress and DNA damage and lead to apoptosis and cell cycle

  20. PET and PET/CT with {sup 18}F-fluoride in the diagnosis of bone metastases; PET und PET/CT mit {sup 18}F-Fluorid in der Diagnostik von Knochenmetastasen

    Energy Technology Data Exchange (ETDEWEB)

    Schmiedel, B.; Palmedo, H. [Klinik und Poliklinik fuer Nuklearmedizin, Universitaetsklinikum Bonn (Germany)

    2006-12-15

    The exact tumor stage needs to be determined with the help of the TNM classification before the optimal therapeutic procedure for the patient is proposed. If M-staging is under question bone metastases must be excluded or be proven. Bone scintigraphy plays a major role for bone metastases screening of patients with lung cancer, prostate and breast cancer in whom osseous disease is often present. The result of bone scintigraphy has a significant impact on further therapy e.g. whether curative treatment is possible, whether operative resection or chemotherapy must be performed. PET and PET/CT with {sup 18}F sodium fluoride are new imaging modalities for the detection of bone metastases. PET with {sup 18}F fluoride allows for cross sectional imaging with high resolution in a way that is not achievable by conventional bone scintigraphy. Pharmacokinetic properties of {sup 18}F fluoride are advantageous and lead to high tracer uptake and quick renal clearance. This allows the acquisition of high quality images as early as one hour after the injection. Compared with planar whole body scintigraphy, {sup 18}F fluoride is able to detect significantly more bone metastases (especially in the vertebral column). In comparison to bone SPECT, less additional metastatic lesions are detected by bone PET. This could be demonstrated in detail for lung and prostate cancers. In a small group of patients, {sup 18}F fluoride will diagnose osseous metastatic disease in spite of a negative planar whole body scintigraphy and a negative bone SPECT. However, specificity of bone SPECT is not markedly improved by {sup 18}F fluoride PET. It seems that new camera systems like PET/CT and SPECT/CT can enhance specificity impressively by adding the CT component to exactly localize a tracer accumulation. (orig.)

  1. Synthesis of complex fluorides for optical applications

    Science.gov (United States)

    Stepleton, Seth Eugene

    Large single crystals of alkali metal fluorides are desirable for many reasons. Fluoride laser crystals have a wide transmission range and on account of their low phonon energies, many efficient laser emissions have been obtained from 285 nm to 4.34 microm.1,2 Inorganic fluoride single crystals feature large bandgaps, very wide optical transmittance ranges from vacuum-ultraviolet (VUV) to mid-IR wavelength regions, lower refractive indices than those of oxides, and typically lower phonon energies (which drastically reduce multiphonon relaxation rates of rare earth ions).3 The main goal of this work was to investigate the hydrothermal synthesis of alkali metal fluorides. Melt techniques have been used thoroughly to research a variety of fluoride systems and showed many phases that were inaccessible due to incongruent melting or phase stability. The existence of these phases was shown but never characterized or grown as a crystalline material. Solution growth in supercritical water was an ideal way to attempt the synthesis of novel compounds and phases. New synthetic routes to known phases and compounds also arose as a part of this work. Optically clear colorless crystals of K2BeF4 were synthesized up to 2 mm in size, and showed no phase transitions up to 1029 K, which suggests paraelectricitys at room temperature, contradicting previous reports.4 Attempts to incorporate a rare earth ion into the fluoroberyllate lattice proved unsuccessful however reactions between beryllium fluoride and lanthanide fluorides could be exploited as a synthetic route to single crystal rare earth fluorides. Hydrothermal reactions with KF produced crystals of three different phases: hexagonal KY2F7, trigonal KYF4 and orthorhombic K2YF5. All were optically clear, colorless crystals, with the K2YF5 crystals growing the largest. This compound is beneficial due to its application as a radiation dosimeter and laser host. 5,6 Optical quality colorless crystals of RbY2F7 and CsY2F7 up to 4 mm in

  2. Appropriate Real-Time PCR Reference Genes for Fluoride Treatment Studies Performed In Vitro or In Vivo

    Science.gov (United States)

    Faibish, D.; Suzuki, M.; Bartlett, J.D.

    2015-01-01

    Objective Quantitative real-time PCR (qPCR) is routinely performed for experiments designed to identify the molecular mechanisms involved in the pathogenesis of dental fluorosis. Expression of reference gene(s) is expected to remain unchanged in fluoride-treated cells or in rodents relative to the corresponding untreated controls. The aim of this study was to select optimal reference genes for fluoride experiments performed in vitro and in vivo. Design Five candidate genes were evaluated: B2m, Eef1a1, Gapdh, Hprt and Tbp. For in vitro experiments, LS8 cells derived from mouse enamel organ were treated with 0, 1, 3 and/or 5 mM sodium fluoride (NaF) for 6 or 18 hours followed by RNA isolation. For in vivo experiments, six-week old rats were treated with 0 or 100 ppm fluoride as NaF for six weeks at which time RNA was isolated from enamel organs. RNA from cells and enamel organs were reverse-transcribed and stability of gene expression for the candidate reference genes was evaluated by qPCR in treated versus non-treated samples. Results The most stably expressed genes in vitro according to geNorm were B2m and Tbp, and according to Normfinder were Hprt and Gapdh. The most stable genes in vivo were Eef1a1 and Gapdh. Expression of Ddit3, a gene previously shown to be induced by fluoride, was demonstrated to be accurately calculated only when using an optimal reference gene. Conclusions This study identifies suitable reference genes for relative quantification of gene expression by qPCR after fluoride treatment both in cultured cells and in the rodent enamel organ. PMID:26615575

  3. Aluminum microstructures on anodic alumina for aluminum wiring boards.

    Science.gov (United States)

    Jha, Himendra; Kikuchi, Tatsuya; Sakairi, Masatoshi; Takahashi, Hideaki

    2010-03-01

    The paper demonstrates simple methods for the fabrication of aluminum microstructures on the anodic oxide film of aluminum. The aluminum sheets were first engraved (patterned) either by laser beam or by embossing to form deep grooves on the surface. One side of the sheet was then anodized, blocking the other side by using polymer mask to form the anodic alumina. Because of the lower thickness at the bottom part of the grooves, the part was completely anodized before the complete oxidation of the other parts. Such selectively complete anodizing resulted in the patterns of metallic aluminum on anodic alumina. Using the technique, we fabricated microstructures such as line patterns and a simple wiring circuit-board-like structure on the anodic alumina. The aluminum microstructures fabricated by the techniques were embedded in anodic alumina/aluminum sheet, and this technique is promising for applications in electronic packaging and devices.

  4. Comparative evaluation of fluoride release from PRG-composites and compomer on application of topical fluoride: An in-vitro study

    Directory of Open Access Journals (Sweden)

    Dhull K

    2009-03-01

    Full Text Available Aims and Objective: To determine the fluoride release from Giomer and Compomer, using different topical fluoride regimes, and to compare the amount of fluoride release from giomer with that of compomer. Materials and Method: Forty-eight specimens of each giomer and compomer were divided into four treatment groups, namely, control group, fluoridated dentifrice (500 ppm once daily group, fluoridated dentifrice (500 ppm twice daily group, fluoridated dentifrice (500 ppm once daily + fluoridated mouthwash (225 ppm group. Each specimen was suspended in demineralizing solution for six hours and remineralizing solution for 18 hours. Fluoride release was measured in both the demineralizing solution and remineralizing solution daily for seven days. Total daily fluoride release for each specimen was calculated by adding the amount released in the demineralizing solution to that released in remineralizing solution. Results and Conclusion: The fluoride release (ppm was found to be more in Giomer when compared to Compomer. The fluoride released from Giomer and Compomer was significantly greater in the acidic demineralizing solution than in the neutral remineralizing solution. It was found that increasing fluoride exposure significantly increased fluoride release from the giomer and compomer. It was found that the fluoride release from the subgroups of giomer and compomer was in the following order: fluoridated dentifrice twice daily > fluoridated dentifrice once daily + fluoridated mouthwash > fluoridated dentifrice once daily > control group. It was found that the giomer showed a greater fluoride uptake than the compomer.

  5. Relationship of phosphatidylinositol bisphosphate hydrolysis to calcium mobilization and functional activation in fluoride-treated neutrophils.

    Science.gov (United States)

    English, D; Debono, D J; Gabig, T G

    1987-07-01

    Sodium fluoride (20 mM) effected rapid hydrolysis of phosphatidylinositol bisphosphate (PIP2) in human neutrophils. Intracellular free Ca2+ levels increased after PIP2 hydrolysis but before respiratory burst activation. Both the increase in intracellular free Ca2+ levels and the extent of functional activation were dependent on the availability of extracellular Ca2+. The rate of F(-)-stimulated PIP2 hydrolysis, however, was not affected when the rise in cytosolic Ca2+ was severely limited by depletion of extracellular Ca2+. Fluoride caused the specific hydrolysis of PIP2 in isolated neutrophil plasma membranes. This effect occurred in the presence of low levels of available Ca2+ and was accompanied by the release of inositol phosphates. We conclude that PIP2 hydrolysis is an early event in the response of neutrophils to F-. This response is not Ca2+-regulated but may lead to an influx of Ca2+ from the extracellular medium. Activation of a PIP2-specific phospholipase independent of a change in cytosolic free Ca2+ levels may be the initial event in the stimulus-response pathway triggered by fluoride.

  6. Fluoride in Drinking Water -Its Effects and Removal

    Directory of Open Access Journals (Sweden)

    Ram Gopal

    1985-01-01

    Full Text Available Occurrence of fluoride in water, its metabolism, excretion. effect oingestion in human and cattle system and methods of fluoridation and defluoridation have been discussed. The presence of fluoride in waters occurring in India, with special reference to Rajasthan desert has been reviewed. Based on the survey and physico-chemical analyses of about 2,700 water samples of Rajasthan, distribution of fluoride in this area has been discussed wrth reference to drinking water standards. A water resources map showing concentrations of fluoride in four arid districts of Rajasthan is also presented.

  7. Vapor Pressure of Aluminum Chloride Systems. 3. Vapor Pressure of Aluminum Chloride-Sodium Chloride Melts

    Science.gov (United States)

    1977-06-23

    were all as described previously (10). A .XCp/R log T(1, 2). mercury manometer was used as n additional external piessure The data were least-squares...the use of a mercury manometer and a NMLeod gauge, respectively, for pressure measurement; all other pressure measurements were made with a

  8. [Chemical form changes of exogenous water solution fluoride and bioavailability in tea garden soil].

    Science.gov (United States)

    Cai, Hui-Mei; Peng, Chuan-Yi; Chen, Jing; Hou, Ru-Yan; Wan, Xiao-Chun

    2013-11-01

    Pot experiments and the sequential extraction method were conducted to study the chemical form changes of exogenous water solution fluoride in tea garden soil and their contribution to fluoride accumulation of tea plant. The results showed that the background concentration of all chemical forms of fluoride had little changes with time treatment, which was in a relatively stable state. The exogenous water solution fluoride adding to the soils was rapidly transformed to other fractions. Under the 10 mg x kg(-1) fluoride treatment, the concentration of water solution fluoride increased firstly and then decreased with time treatment, the concentration of organic matter fluoride and Fe/Mn oxides fluoride decreased, the concentration of exchangeable fluoride was not different before and after the treatment (P > 0.05), and the concentration of residual fluoride was in a relatively stable state; under the 200 mg x kg(-1) fluoride treatment, the concentration of water solution fluoride, Fe/Mn oxides fluoride and organic matter fluoride decreased with time treatment, the concentration of exchangeable fluoride increased firstly and then decreased, showed no difference before and after the treatment (P > 0.05), and the concentration of residual fluoride increased, with some differences compared with 10 mg x kg(-1) fluoride treatment. The concentration of total fluoride in root, stem and leaf had significant differences under 0-10 mg x kg(-1) fluoride treatment (P treatment (P > 0.05). Step regression analysis suggested the contribution of all chemical forms of fluoride to the concentration of water solution fluoride and total fluoride of root, stem and leaf had some differences, there was a remarkable regression relationship among the content of total fluoride in leaf and water solution fluoride, organic matter fluoride, Fe/Mn oxides fluoride and residual fluoride in soil, however, no significant difference for water solution fluoride of leaf was found.

  9. Aluminum Carbothermic Technology

    Energy Technology Data Exchange (ETDEWEB)

    Bruno, Marshall J.

    2005-03-31

    This report documents the non-proprietary research and development conducted on the Aluminum Carbothermic Technology (ACT) project from contract inception on July 01, 2000 to termination on December 31, 2004. The objectives of the program were to demonstrate the technical and economic feasibility of a new carbothermic process for producing commercial grade aluminum, designated as the ''Advanced Reactor Process'' (ARP). The scope of the program ranged from fundamental research through small scale laboratory experiments (65 kW power input) to larger scale test modules at up to 1600 kW power input. The tasks included work on four components of the process, Stages 1 and 2 of the reactor, vapor recovery and metal alloy decarbonization; development of computer models; and economic analyses of capital and operating costs. Justification for developing a new, carbothermic route to aluminum production is defined by the potential benefits in reduced energy, lower costs and more favorable environmental characteristics than the conventional Hall-Heroult process presently used by the industry. The estimated metrics for these advantages include energy rates at approximately 10 kWh/kg Al (versus over 13 kWh/kg Al for Hall-Heroult), capital costs as low as $1250 per MTY (versus 4,000 per MTY for Hall-Heroult), operating cost reductions of over 10%, and up to 37% reduction in CO2 emissions for fossil-fuel power plants. Realization of these benefits would be critical to sustaining the US aluminum industries position as a global leader in primary aluminum production. One very attractive incentive for ARP is its perceived ability to cost effectively produce metal over a range of smelter sizes, not feasible for Hall-Heroult plants which must be large, 240,000 TPY or more, to be economical. Lower capacity stand alone carbothermic smelters could be utilized to supply molten metal at fabrication facilities similar to the mini-mill concept employed by the steel industry

  10. Adsorption behavior of condensed phosphate on aluminum hydroxide

    Institute of Scientific and Technical Information of China (English)

    GUAN Xiao-hong; CHEN Guang-hao; SHANG Chii

    2007-01-01

    Sodium pyrophosphate(pyro-P,Na4P207),sodium tripolyphosphate(tripoly-P,NasP3010),and sodium hexametaphosphate(metaP,(NaP03)6)were selected as the model compounds of condensed phosphate to investigate the adsorption behavior of condensed phosphate on aluminum hydroxide.The adsorption was found to be endothermic and divisible into two stages:(1)fast adsorption within 1 h:and(2)slow adsorption between 1 and 24 h.The modified Freundlich model simulated the fast adsorption stage well;the slow adsorption stage was described well by the first-order kinetics.The activation energies of pyro-P,tripoly-P,and meta-P adsorption on aluminum hydroxide were determined to be 20.2,22.8 and 10.9 kJ/mol P adsorbed,respectively,in the fast adsorption stage and to be 66.3.53.5 and 72.5 kJ/tool P adsorbed,respectively,in the slow adsorption stage.The adsorption increased the negative charge of the aluminum hydroxide surface.Transmission electron microscopy and energy dispersive X-ray analysis analyses provided evidence that the adsorption was not uniform on the surface and that the small crystals contfibuted more to the fast adsorption than the normal sites did.The results from X-ray fluorescence spectrometry and X-ray photoelectron spectroscopy tests also revealed the uneven adsorption of condensed phosphate as a function of the penetration depth.More condensed phosphates were adsorbed on the outer surface of aluminum hydroxide than in its inner parts.

  11. Estimated Fluoride Doses from Toothpastes Should be Based on Total Soluble Fluoride

    Directory of Open Access Journals (Sweden)

    Jaime A. Cury

    2013-11-01

    Full Text Available The fluoride dose ingested by young children may be overestimated if based on levels of total fluoride (TF rather than levels of bioavailable fluoride (total soluble fluoride—TSF in toothpaste. The aim of the present study was to compare doses of fluoride intake based on TF and TSF. Fluoride intake in 158 Brazilian children aged three and four years was determined after tooth brushing with their usual toothpaste (either family toothpaste (n = 80 or children’s toothpaste (n = 78. The estimated dose (mg F/day/Kg of body weight of TF or TSF ingested was calculated from the chemical analysis of the toothpastes. Although the ingested dose of TF from the family toothpastes was higher than that from the children’s toothpastes (0.074 ± 0.007 and 0.039 ± 0.003 mg F/day/Kg, respectively; p 0.05. The fluoride dose ingested by children from toothpastes may be overestimated if based on the TF of the product. This finding suggests that the ingested dose should be calculated based on TSF. Dose of TSF ingested by children is similar whether family or children’s toothpaste is used.

  12. Zirconium fluoride glass - Surface crystals formed by reaction with water

    Science.gov (United States)

    Doremus, R. H.; Bansal, N. P.; Bradner, T.; Murphy, D.

    1984-01-01

    The hydrated surfaces of a zirconium barium fluoride glass, which has potential for application in optical fibers and other optical elements, were observed by scanning electron microscopy. Crystalline zirconium fluoride was identified by analysis of X-ray diffraction patterns of the surface crystals and found to be the main constituent of the surface material. It was also found that hydrated zirconium fluorides form only in highly acidic fluoride solutions. It is possible that the zirconium fluoride crystals form directly on the glass surface as a result of its depletion of other ions. The solubility of zirconium fluoride is suggested to be probably much lower than that of barium fluoride (0.16 g/100 cu cm at 18 C). Dissolution was determined to be the predominant process in the initial stages of the reaction of the glass with water. Penetration of water into the glass has little effect.

  13. Oral fluoride retention after professional topical application in children with caries activity: comparison between 1.23% fluoride foam and fluoride gel

    Directory of Open Access Journals (Sweden)

    Cecília Claudia Costa Ribeiro

    2008-01-01

    Full Text Available Objective: This study evaluated fluoride retention in the saliva of children with caries activity after topical fluoride application in the form of gel and foam. Methods: A cross-sectional, blind and randomized study, conducted with ten caries-active children aged between 8 and 10 years, in two stage, with a washout interval of two weeks between them. The treatments consisted of: a application of 2mL acidulated phosphate fluoride of the gel type in a mold and b application of 2mL acidulated phosphate fluoride of the foam type in a mold. After the washout, the treatments were inverted. Non-stimulated saliva was collected from the children at the times of 5, 15, 30 and 60 minutes after topical fluoride application. For statistical analysis the Student’s-t test was used, with a level of significance of 5%. Results: Saliva analysis was performed using a fluoride-specific electrode (ISE25F/ Radiometer, Copenhagen, Denmark at the Aquatic Science Center of the Federal University of Marana, which revealed differences after 5 minutes (p=0.0055 and 15 minutes (p=0.0208. The topical application of fluoride in the gel form revealed a higher concentration of fluoride in the saliva. Conclusion: There were differences in the retention of fluoride in the saliva of children with caries activity after the topical application of fluoride gel and the topical application of fluoride foam after 5 and 15 minutes of their application. The topical application of fluoride foam is recommended, on the basis of the lower probability of toxicity during its use.

  14. Laser assisted foaming of aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Kathuria, Y.P. [Laser X Co. Ltd., Aichi (Japan)

    2001-09-01

    Recently aluminum foams have evoked considerable interest as an alternative material owing to their wide range of applications ranging from microelectronics, through automobiles to aerospace industries. The manufacturing techniques and characterization methods for aluminum foams require further development to achieve effective and economical use of this material. In this communication the authors demonstrate the feasibility of unidirectional and localized expansion of the aluminum foam using the Nd-YAG/CO{sub 2} laser and powder metallurgy. (orig.)

  15. Water fluoridation in 40 Brazilian cities: 7 year analysis

    Directory of Open Access Journals (Sweden)

    Suzely Adas Saliba MOIMAZ

    2013-01-01

    Full Text Available Objectives Fluoride levels in the public water supplies of 40 Brazilian cities were analyzed and classified on the basis of risk/benefit balance. Material and Methods Samples were collected monthly over a seven-year period from three sites for each water supply source. The samples were analyzed in duplicate in the laboratory of the Center for Research in Public Health - UNESP using an ion analyzer coupled to a fluoride-specific electrode. Results A total of 19,533 samples were analyzed, of which 18,847 were artificially fluoridated and 686 were not artificially fluoridated. In samples from cities performing water fluoridation, 51.57% (n=9,720 had fluoride levels in the range of 0.55 to 0.84 mg F/L; 30.53% (n=5,754 were below 0.55 mg F/L and 17.90% (n=3,373 were above 0.84 mg F/L (maximum concentration=6.96 mg F/L. Most of the cities performing fluoridation that had a majority of samples with fluoride levels above the recommended parameter had deep wells and more than one source of water supply. There was some variability in the fluoride levels of samples from the same site and between collection sites in the same city. Conclusions The majority of samples from cities performing fluoridation had fluoride levels within the range that provides the best combination of risks and benefits, minimizing the risk of dental fluorosis while preventing dental caries. The conduction of studies about water distribution systems is suggested in cities with high natural fluoride concentrations in order to optimize the use of natural fluoride for fluoridation costs and avoid the risk of dental fluorosis.

  16. APPLICATION OF VACUUM SALT DISTILLATION TECHNOLOGY FOR THE REMOVAL OF FLUORIDE

    Energy Technology Data Exchange (ETDEWEB)

    Pierce, R.; Pak, D.

    2011-08-10

    Vacuum distillation of chloride salts from plutonium oxide (PuO{sub 2}) and simulant PuO{sub 2} has been previously demonstrated at Department of Energy (DOE) sites using kilogram quantities of chloride salt. The apparatus for vacuum distillation contains a zone heated using a furnace and a zone actively cooled using either recirculated water or compressed air. During a vacuum distillation operation, a sample boat containing the feed material is placed into the apparatus while it is cool, and the system is sealed. The system is evacuated using a vacuum pump. Once a sufficient vacuum is attained, heating begins. Volatile salts distill from the heated zone to the cooled zone where they condense, leaving behind the non-volatile materials in the feed boat. The application of vacuum salt distillation (VSD) is of interest to the HB-Line Facility and the MOX Fuel Fabrication Facility (MFFF) at the Savannah River Site (SRS). Both facilities are involved in efforts to disposition excess fissile materials. Many of these materials contain chloride and fluoride salt concentrations which make them unsuitable for dissolution without prior removal of the chloride and fluoride salts. Between September 2009 and January 2011, the Savannah River National Laboratory (SRNL) and HB-Line designed, developed, tested, and successfully deployed a system for the distillation of chloride salts. Subsequent efforts are attempting to adapt the technology for the removal of fluoride. Fluoride salts of interest are less-volatile than the corresponding chloride salts. Consequently, an alternate approach is required for the removal of fluoride without significantly increasing the operating temperature. HB-Line Engineering requested SRNL to evaluate and demonstrate the feasibility of an alternate approach using both non-radioactive simulants and plutonium-bearing materials. Whereas the earlier developments targeted the removal of sodium chloride (NaCl) and potassium chloride (KCl), the current

  17. Water Fluoridation: A Critical Review of the Physiological Effects of Ingested Fluoride as a Public Health Intervention

    Directory of Open Access Journals (Sweden)

    Stephen Peckham

    2014-01-01

    Full Text Available Fluorine is the world’s 13th most abundant element and constitutes 0.08% of the Earth crust. It has the highest electronegativity of all elements. Fluoride is widely distributed in the environment, occurring in the air, soils, rocks, and water. Although fluoride is used industrially in a fluorine compound, the manufacture of ceramics, pesticides, aerosol propellants, refrigerants, glassware, and Teflon cookware, it is a generally unwanted byproduct of aluminium, fertilizer, and iron ore manufacture. The medicinal use of fluorides for the prevention of dental caries began in January 1945 when community water supplies in Grand Rapids, United States, were fluoridated to a level of 1 ppm as a dental caries prevention measure. However, water fluoridation remains a controversial public health measure. This paper reviews the human health effects of fluoride. The authors conclude that available evidence suggests that fluoride has a potential to cause major adverse human health problems, while having only a modest dental caries prevention effect. As part of efforts to reduce hazardous fluoride ingestion, the practice of artificial water fluoridation should be reconsidered globally, while industrial safety measures need to be tightened in order to reduce unethical discharge of fluoride compounds into the environment. Public health approaches for global dental caries reduction that do not involve systemic ingestion of fluoride are urgently needed.

  18. THE DIGESTION OPERATION IN THE ALKALI ALUMINAT SOLUTIONS OF ALUMINUM HYDROXIDES IN THE BOEHMITIC BAUXITES

    Directory of Open Access Journals (Sweden)

    Sami ŞAHİN

    1999-01-01

    Full Text Available At present more than 90 per cent of the world's alumina is produced by the Bayer process, a simple technology providing high purity final product. A part from some exceptional local conditions, bauxite is processed almost solely by this technology. As a benefication process, alumina production releases the aluminum oxide content of bauxite from other accompanying oxides thus providing alumina suitable for electrolysis in a cryolite melt. The basic theory of the Bayer process was elaborated by K.J. Bayer and described in his patents in 1887 and 1892. The first patent refers to the aid of seed crystals of aluminum hydroxide or of carbonic acid, that is, to the precipitation and carbonation processes. The second patent formulates the concept that the aluminum oxide content of bauxites can be dissolved in sodium hydroxide solutions, with the formulation of sodium aluminate, a process called digestion nowadays. The most important operations of the Bayer technology are bauxite preparation, crushing, grinding, digestion, red mud separation, thickening, washing, filtration, precipitation, calcination and evaporation. In spite of its great significance as regards the complete Bayer technology, the structure of sodium aluminate solutions has not been cleared up definitely yet. Boehmite is the most important aluminum mineral of karstic bauxites. Some experimental results showing the various effects on aluminum hydroxides by alkali process from boehmitic bauxites and the factors gowerning the digestion operation of aluminate solutions were investigated.

  19. Protective effect of lycopene on fluoride-induced ameloblasts apoptosis and dental fluorosis through oxidative stress-mediated Caspase pathways.

    Science.gov (United States)

    Li, Weishan; Jiang, Binghua; Cao, Xianglin; Xie, Yongjiang; Huang, Ting

    2017-01-05

    Fluoride is an environmental toxicant and induces dental fluorosis and oxidative stress. Lycopene (LYC) is an effective antioxidant that is reported to attenuate fluoride toxicity. To determine the effects of LYC on sodium fluoride (NaF) -induced teeth and ameloblasts toxicity, rats were treated with NaF (10 mg/kg) and/or LYC (10 mg/kg) by orally administration for 5 weeks; ameloblasts were treated with NaF (5 mM) and/or LYC (2 μM) for 6 h. We found that the concentrations of fluoride, malondialdehyde (MDA) and reactive oxygen species (ROS), gene expressions and activities of Caspase-9 and Caspase-3, and the gene expressions of Bax were significantly decreased, while the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPX), the gene expression of Bcl-2 were significantly increased in the LYC + NaF-treated rats group; concentrations of MDA and ROS, gene expressions and activities of Caspase-9 and Caspase-3, and the gene expression of Bax, and ameloblasts apoptosis rate were significantly decreased, while the activities of SOD and GPX, the gene expression of Bcl-2 were significantly increased in the LYC + NaF-treated ameloblasts group. These results suggest that LYC significantly combated NaF-induced ameloblasts apoptosis and dental fluorosis by attenuation oxidative stress and down-regulation Caspase pathway.

  20. Chemical and morphological features of nanofilled composite resin: influence of finishing and polishing procedures and fluoride solutions.

    Science.gov (United States)

    de Oliveira, Ana Luísa Botta Martins; Domingos, Patrícia Aleixo Dos Santos; Palma-Dibb, Regina Guenka; Garcia, Patrícia Petromilli Nordi Sasso

    2012-02-01

    This study evaluated the influence of finishing and polishing procedures and different fluoride solutions on superficial morphology and chemistry of the nanofilled composite resin Supreme XT (3M) through the EDX analysis and SEM evaluation. Circular specimens (n = 30) of 10 mm diameter and 2 mm thickness were prepared, with half of the sample assays finished and polished with Super-Snap® sandpaper. The experimental groups were divided according to the presence or absence of finishing and polishing and solutions (artificial saliva, 0.05% of manipulated sodium fluoride solution, Fluordent Reach, Oral B, Fluorgard). Specimens were immersed in each respective solution for 1 min per day, during 60 days and stored in artificial saliva at 37 ± 1°C between immersion periods. Topography and chemical analysis was qualitative. It was observed that specimens submitted to finishing and polishing procedures had lower superficial degradation. Fluoride solutions promoted superficial alterations on specimens, being the highest degradation obtained with Fluordent Reach. It can be concluded that finishing and polishing procedures and the immersion media influence the superficial morphology of composite resin tested; the Fluordent Reach was the fluoride solution that most affected the material's surface.

  1. The geochemical evolution of aqueous sodium in the Black Creek Aquifer, Horry and Georgetown counties, South Carolina

    Science.gov (United States)

    Zack, Allen L.; Roberts, Ivan

    1988-01-01

    The Black Creek aquifer contains dilute seawater near the North Carolina State line, probably the result of incomplete flushing of ancient seawater. Data do not indicate that the dilute seawater has migrated toward areas of fresh ground-water withdrawals. The concentration of chloride in ground-water samples ranges from 5 to 720 milligrams per liter and that of sodium from 160 to 690 milligrams per liter. Ion-exchange reactions (sodium for calcium and fluoride for hydroxyl) occur with the calcium carbonate dissolution reaction which produces calcium, bicarbonate, and hydroxyl ions. The reaction sequence and stoichiometry result in an aqueous solution in which the sum of bicarbonate and chloride equivalents per liter is equal to the equivalents per liter of sodium. Calcium ions are exchanged for sodium ions derived from sodium-rich clays upgradient of the dilute seawater. The cation-exchange reaction equilibrates at a sodium concentration of 280 milligrams per liter. Amounts of sodium greater than 280 milligrams per liter are contributed from dilute seawater. The cation-exchange reaction approaches an equilibrium which represents a mass-action limit in terms of the ratio of sodium to calcium in solution versus the ratio of exchangeable sodium to calcium on clay surfaces. Where the limit of calcium carbonate solubility is approached and dissolution ceases, some precipitation of calcite probably takes place. The dissolution of calcite exposes fossil shark teeth which release fluoride ions to the ground water through anion exchange with aqueous hydroxyl ions.

  2. Enabling room temperature sodium metal batteries

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Ruiguo; Mushra, Kuber; Li, Xiaolin; Qian, Jiangfeng; Engelhard, Mark H.; Bowden, Mark E.; Han, Kee Sung; Mueller, Karl T.; Henderson, Wesley A.; Zhang, Jiguang

    2016-12-01

    Rechargeable batteries based upon sodium (Na+) cations are at the core of many new battery chemistries beyond Li-ion batteries. Rather than using carbon or alloy-based anodes, the direct utilization of solid sodium metal as an anode would be highly advantageous, but its use has been highly problematic due to its high reactivity. In this work, however, it is demonstrated that, by tailoring the electrolyte formulation, solid Na metal can be electrochemically plated/stripped at ambient temperature with high efficiency (> 99%) on both copper and inexpensive aluminum current collectors thereby enabling a shift in focus to new battery chemical couples based upon Na metal operating at ambient temperature. These highly concentrated electrolytes has enabled stable cycling of Na metal batteries based on a Na metal anode and Na3V2(PO4)3 cathode at high rates with very high efficiency.

  3. Diclofenac sodium overdose

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/002630.htm Diclofenac sodium overdose To use the sharing features on this page, please enable JavaScript. Diclofenac sodium is a prescription medicine used to relieve pain ...

  4. Naproxen sodium overdose

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/002507.htm Naproxen sodium overdose To use the sharing features on this page, please enable JavaScript. Naproxen sodium is a nonsteroidal anti-inflammatory drug (NSAID) used ...

  5. Docusate Sodium and Pregnancy

    Science.gov (United States)

    ... live chat Live Help Fact Sheets Share Docusate Sodium Friday, 01 April 2016 In every pregnancy, a ... This sheet talks about whether exposure to docusate sodium may increase the risk for birth defects over ...

  6. Sodium hydroxide poisoning

    Science.gov (United States)

    Sodium hydroxide is a very strong chemical. It is also known as lye and caustic soda. This ... poisoning from touching, breathing in (inhaling), or swallowing sodium hydroxide. This article is for information only. Do ...

  7. Sodium carbonate poisoning

    Science.gov (United States)

    Sodium carbonate (known as washing soda or soda ash) is a chemical found in many household and ... products. This article focuses on poisoning due to sodium carbonate. This article is for information only. Do ...

  8. Sodium Ferric Gluconate Injection

    Science.gov (United States)

    Sodium ferric gluconate injection is used to treat iron-deficiency anemia (a lower than normal number of ... are also receiving the medication epoetin (Epogen, Procrit). Sodium ferric gluconate injection is in a class of ...

  9. Erratum to "Clinical evaluation of the intraoral fluoride releasing system in radiation-induced xerostomic subjects. Part 2: Phase I study".

    Science.gov (United States)

    Chambers, Mark S; Fleming, Terence J; Toth, Béla B; Lemon, James C; Craven, Timothy E; Bouwsma, Otis J; Garden, Adam S; Espeland, Mark A; Keene, Harris J; Martin, Jack W; Sipos, Tibor

    2007-01-01

    Radiation-induced xerostomia can result in the rapid onset and progression of dental caries in head and neck cancer patients. Topically applied fluorides have been successfully used to inhibit the formation of dental caries in this population. However, because intensive daily self-application is required, compliance is an issue. The intraoral fluoride-releasing system (IFRS) containing a sodium fluoride core is a newly developed, sustained-release, passive drug delivery system that does not require patient involvement except for periodic replacement, thus reducing the effect of patient compliance on its effectiveness in dental caries prevention. Twenty-two head and neck cancer patients from U. T. M. D. Anderson Cancer Center, with radiation-induced xerostomia, were entered into a pilot study to contrast the daily home use of a 0.4% stannous fluoride-gel-containing tray (control group) to IFRS (study group) with respect to tolerability and adherence, and to obtain information on relative caries preventive efficacy. Participants were stratified on the basis of radiation exposure and randomly assigned to treatment with either IFRS or stannous fluoride gel. Patients in both groups were fitted with two IFRS retainers and also were instructed to use a 1100-ppm fluoride conventional sodium fluoride dentifrice twice daily. The study was conducted as a single-blinded, parallel-cell trial. Pre-existing carious lesions were restored prior to the beginning of the study. The efficacy variable was determined by the mean number of new or recurrent decayed surfaces. Patients were examined for caries 4, 8, 12, 24, 36, and 48 weeks after initiation of treatment. Reports of adverse reactions were based on information volunteered by patients and that were elicited during interviews. At baseline, the resting and stimulated salivary flow rates (g/5min) were significantly greater in the control group than in the study group (pIFRS groups during the study period. The rate of new or

  10. ALUMINUM REMOVAL FROM HANFORD WASTE BY LITHIUM HYDROTALCITE PRECIPITATION - LABORATORY SCALE VALIDATION ON WASTE SIMULANTS TEST REPORT

    Energy Technology Data Exchange (ETDEWEB)

    SAMS T; HAGERTY K

    2011-01-27

    To reduce the additional sodium hydroxide and ease processing of aluminum bearing sludge, the lithium hydrotalcite (LiHT) process has been invented by AREV A and demonstrated on a laboratory scale to remove alumina and regenerate/recycle sodium hydroxide prior to processing in the WTP. The method uses lithium hydroxide (LiOH) to precipitate sodium aluminate (NaAI(OH){sub 4}) as lithium hydrotalcite (Li{sub 2}CO{sub 3}.4Al(OH){sub 3}.3H{sub 2}O) while generating sodium hydroxide (NaOH). In addition, phosphate substitutes in the reaction to a high degree, also as a filterable solid. The sodium hydroxide enriched leachate is depleted in aluminum and phosphate, and is recycled to double-shell tanks (DSTs) to leach aluminum bearing sludges. This method eliminates importing sodium hydroxide to leach alumina sludge and eliminates a large fraction of the total sludge mass to be treated by the WTP. Plugging of process equipment is reduced by removal of both aluminum and phosphate in the tank wastes. Laboratory tests were conducted to verify the efficacy of the process and confirm the results of previous tests. These tests used both single-shell tank (SST) and DST simulants.

  11. Minimum and Full Fluidization Velocity for Alumina Used in the Aluminum Smelter

    Directory of Open Access Journals (Sweden)

    Paulo Douglas S. de Vasconcelos

    2011-11-01

    Full Text Available Fluidization is an engineering unit operation that occurs when a fluid (liquid or gas ascends through a bed of particles, and these particles get a velocity of minimum fluidization enough to stay in suspension, but without carrying them in the ascending flow. As from this moment the powder behaves as liquid at boiling point, hence the term “fluidization”. This operation is widely used in the aluminum smelter processes, for gas dry scrubbing (mass transfer and in a modern plant for continuous alumina pot feeding (particles’ momentum transfer. The understanding of the alumina fluoride rheology is of vital importance in the design of fluidized beds for gas treatment and fluidized pipelines for pot feeding. This paper shows the results of the experimental and theoretical values of the minimum and full fluidization velocities for the alumina fluoride used to project the state of the art round non‐metallic air‐fluidized conveyor of multiples outlets.

  12. Neurofibrillary pathology and aluminum in Alzheimer's disease

    OpenAIRE

    Shin, R. W.; Lee, V.M.Y.; Trojanowski, J.Q.

    1995-01-01

    Since the first reports of aluminum-induced neurofibrillary degeneration in experimental animals, extensive studies have been performed to clarify the role played by aluminum in the pathogenesis of Alzheimer's disease (AD). Additional evidence implicating aluminum in AD includes elevated levels of aluminum in the AD brain, epidemiological data linking aluminum exposure to AD, and interactions between aluminum and protein components in the pathological lesions o...

  13. Chemical equilibrium modeling of organic acids, pH, aluminum, and iron in Swedish surface waters.

    Science.gov (United States)

    Sjöstedt, Carin S; Gustafsson, Jon Petter; Köhler, Stephan J

    2010-11-15

    A consistent chemical equilibrium model that calculates pH from charge balance constraints and aluminum and iron speciation in the presence of natural organic matter is presented. The model requires input data for total aluminum, iron, organic carbon, fluoride, sulfate, and charge balance ANC. The model is calibrated to pH measurements (n = 322) by adjusting the fraction of active organic matter only, which results in an error of pH prediction on average below 0.2 pH units. The small systematic discrepancy between the analytical results for the monomeric aluminum fractionation and the model results is corrected for separately for two different fractionation techniques (n = 499) and validated on a large number (n = 3419) of geographically widely spread samples all over Sweden. The resulting average error for inorganic monomeric aluminum is around 1 µM. In its present form the model is the first internally consistent modeling approach for Sweden and may now be used as a tool for environmental quality management. Soil gibbsite with a log *Ks of 8.29 at 25°C together with a pH dependent loading function that uses molar Al/C ratios describes the amount of aluminum in solution in the presence of organic matter if the pH is roughly above 6.0.

  14. Effects of long term exposure to hydrogen fluoride on grapevines

    Energy Technology Data Exchange (ETDEWEB)

    Murray, F.

    1984-01-01

    Grapevines Vitis vinifera L. Shiraz were exposed to hydrogen fluoride in open-top chambers for 189 days at mean atmospheric fluoride concentrations of 0.27, 0.17 or 0.07 ..mu..g HFm/sup -3/. Grapevines growing under ambient conditions outside the chambers were exposed to a mean atmospheric fluoride concentration of 0.08 ..mu..g HFm/sup -3/. The maximum leaf fluoride concentrations associated with these treatments were 62, 27, 9 and 15 ..mu..g Fg/sup -1/, respectively. Foliar necrosis was first observed on grapevines exposed to 0.27 and 0.17 ..mu..g HFm/sup -3/ after 83 and 99 days, respectively. Exposure to fluoride increased the fluoride content of berries and peduncles, and reduced leaf chlorophyll a and total chlorophyll concentration at both mid-season and harvest. Exposure to 0.17 ..mu..g HF m/sup -3/ was associated with higher total acid content of grapes than other treatments. Fluoride had no significant effect on bunch weight, number of bunches, grape yield, grape water or potential alcohol content, leaf chlorophyll b or leaf protein concentration. The high accumulation of fluoride in peduncles, but low fluoride accumulation in berries, suggests that the peduncle acts to block the translocation of fluoride from sites of uptake to the fruit. 42 references, 1 figure, 5 tables.

  15. Caries prevention through the fluoridation of milk. A review.

    Science.gov (United States)

    Bánóczy, Jolán; Rugg-Gunn, Andrew J

    2007-10-01

    The aim of this review is to give an overview of 50 years experience of milk fluoridation and draw conclusions about the applicability of the method. Fluoridated milk was first investigated in the early 1950s, almost simultaneously in Switzerland, the USA and Japan. Stimulated by the favourable results obtained from these early studies, the establishment of The Borrow Dental Milk Foundation (subsequently The Borrow Foundation) in England gave an excellent opportunity for further research, both clinical and non-clinical, and a productive collaboration with the World Health Organization from the early 1980s onwards. Numerous peer-reviewed publications in international journals showed clearly the bioavailability of fluoride in milk, and increased concentrations of fluoride in saliva, dental plaque, dental enamel and dentine, and urine, after consumption of fluoridated milk. Clinical trials were initiated in the 1980s--some of these can be classed as randomised controlled trials, while most of the clinical studies were community preventive programs. These evaluations showed clearly that the optimal daily intake of fluoride in milk is effective in preventing dental caries. At present, milk fluoridation programs are running continuously in about ten countries of the world. Fluoridation of milk can be recommended as a caries preventive measure where the fluoride concentration in drinking water is suboptimal, caries experience in children is significant, and there is an existing school milk program. The program should aim to provide fluoridated milk for at least 200 days per year and should commence before the children are 4 years of age.

  16. Arsenic from community water fluoridation: quantifying the effect.

    Science.gov (United States)

    Peterson, Emily; Shapiro, Howard; Li, Ye; Minnery, John G; Copes, Ray

    2016-04-01

    Community water fluoridation is a WHO recommended strategy to prevent dental carries. One debated concern is that hydrofluorosilicic acid, used to fluoridate water, contains arsenic and poses a health risk. This study was undertaken to determine if fluoridation contributes to arsenic in drinking water, to estimate the amount of additional arsenic associated with fluoridation, and compare this to the National Sanitation Foundation/American National Standards Institute (NSF/ANSI) standard and estimates from other researchers. Using surveillance data from Ontario drinking water systems, mixed effects linear regression was performed to examine the effect of fluoridation status on the difference in arsenic concentration between raw water and treated water samples. On average, drinking water treatment was found to reduce arsenic levels in water in both fluoridated and non-fluoridated systems by 0.2 μg/L. However, fluoridated systems were associated with an additional 0.078 μg/L (95% CI 0.021, 0.136) of arsenic in water when compared to non-fluoridated systems (P = 0.008) while controlling for raw water arsenic concentrations, types of treatment processes, and source water type. Our estimate is consistent with concentrations expected from other research and is less than 10% of the NSF/ANSI standard of 1 μg/L arsenic in water. This study provides further information to inform decision-making regarding community water fluoridation.

  17. Parabens do not increase fluoride uptake by dental enamel

    Directory of Open Access Journals (Sweden)

    Vanessa Silva Tramontino

    2010-04-01

    Full Text Available Objective: To evaluate whether methylparaben and propylparaben, which present a similar chemical structure, increase fluoride uptake by demineralized dental enamel when present in buffered solutions. Methods: The study comprised an in vitro experiment using blocks of bovine dental enamel with artificial carious lesions. Enamel blocks were exposed to the following treatment (n=12: fluoride solution (200 ppm fluoride - control; solution containing fluoride and 13 mM methylparaben; solution containing fluoride and 13 mM propylparaben in 35% propylene glycol; solution containing fluoride in 35% propylene glycol. All solutions were buffered (0.01 M cacodilate and the pH was adjusted to 6.27. The blocks were exposed to the treatment solutions in the proportion of 2 ml per mm2 of exposed enamel area and fluoride formed was estimated after removing an enamel layer by acid etching. Fluoride extracted was determined by ion specific electrode and the amount of enamel removed was estimated by phosphorus analysis. ANOVA followed by Tukey’s test were used for statistical analysis, with significance level at 5%. Results: The dental blocks of treatment groups containing both parabens and the control group presented similar fluoride concentration in enamel and no statistical difference was observed among them (p>0.05. The dental blocks of treatment group containing fluoride and propylene glycol showed the lowest value of fluoride present in enamel, which was significantly different from the control and fluoride and methylparaben groups (p<0.05. Conclusion: Methyl and propylparaben in a buffered solution do not enhance fluoride uptake by demineralized dental enamel.

  18. Nanocomposite anode materials for sodium-ion batteries

    Science.gov (United States)

    Manthiram, Arumugam; Kim Il, Tae; Allcorn, Eric

    2016-06-14

    The disclosure relates to an anode material for a sodium-ion battery having the general formula AO.sub.x--C or AC.sub.x--C, where A is aluminum (Al), magnesium (Mg), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), zirconium (Zr), molybdenum (Mo), tungsten (W), niobium (Nb), tantalum (Ta), silicon (Si), or any combinations thereof. The anode material also contains an electrochemically active nanoparticles within the matrix. The nanoparticle may react with sodium ion (Na.sup.+) when placed in the anode of a sodium-ion battery. In more specific embodiments, the anode material may have the general formula M.sub.ySb-M'O.sub.x--C, Sb-MO.sub.x--C, M.sub.ySn-M'C.sub.x--C, or Sn-MC.sub.x--C. The disclosure also relates to rechargeable sodium-ion batteries containing these materials and methods of making these materials.

  19. Aluminium fluoride and magnesium, activators of heterotrimeric GTP-binding proteins, affect high-affinity binding of the fungal toxin fusicoccin to the fusicoccin-binding protein in oat root plasma membranes.

    NARCIS (Netherlands)

    de Boer, A.H.; Van der Molen, G.W.; Prins, H.B.A.; Korthout, H.A.A.J.; van der Hoeven, P.C.J.

    1994-01-01

    The fusicoccin-binding protein was solubilised from purified oat root plasma membranes. The solubilised protein retained full binding activity, provided that protease inhibitors were included. Sodium fluoride reduced the high-affinity [H-3]fusicoccin binding to almost zero in a concentration-depende

  20. Aluminum Nanoholes for Optical Biosensing

    Directory of Open Access Journals (Sweden)

    Carlos Angulo Barrios

    2015-07-01

    Full Text Available Sub-wavelength diameter holes in thin metal layers can exhibit remarkable optical features that make them highly suitable for (biosensing applications. Either as efficient light scattering centers for surface plasmon excitation or metal-clad optical waveguides, they are able to form strongly localized optical fields that can effectively interact with biomolecules and/or nanoparticles on the nanoscale. As the metal of choice, aluminum exhibits good optical and electrical properties, is easy to manufacture and process and, unlike gold and silver, its low cost makes it very promising for commercial applications. However, aluminum has been scarcely used for biosensing purposes due to corrosion and pitting issues. In this short review, we show our recent achievements on aluminum nanohole platforms for (biosensing. These include a method to circumvent aluminum degradation—which has been successfully applied to the demonstration of aluminum nanohole array (NHA immunosensors based on both, glass and polycarbonate compact discs supports—the use of aluminum nanoholes operating as optical waveguides for synthesizing submicron-sized molecularly imprinted polymers by local photopolymerization, and a technique for fabricating transferable aluminum NHAs onto flexible pressure-sensitive adhesive tapes, which could facilitate the development of a wearable technology based on aluminum NHAs.

  1. Ballistic Evaluation of 2060 Aluminum

    Science.gov (United States)

    2016-05-24

    experiments in Experimental Facilities (EFs) 108 and 106, as well as John Hogan of ARL/AMB, Hugh Walter of Bowhead Science and Technology, and David Handshoe...new aluminum (Al)-based monocoque armored-vehicle hulls such as those of the M2 Bradley Infantry Fighting Vehicles. Also in 2012 the Aluminum

  2. Wettability of Aluminum on Alumina

    Science.gov (United States)

    Bao, Sarina; Tang, Kai; Kvithyld, Anne; Tangstad, Merete; Engh, Thorvald Abel

    2011-12-01

    The wettability of molten aluminum on solid alumina substrate has been investigated by the sessile drop technique in a 10-8 bar vacuum or under argon atmosphere in the temperature range from 1273 K to 1673 K (1000 °C to 1400 °C). It is shown that the reduction of oxide skin on molten aluminum is slow under normal pressures even with ultralow oxygen potential, but it is enhanced in high vacuum. To describe the wetting behavior of the Al-Al2O3 system at lower temperatures, a semiempirical calculation was employed. The calculated contact angle at 973 K (700 °C) is approximately 97 deg, which indicates that aluminum does not wet alumina at aluminum casting temperatures. Thus, a priming height is required for aluminum to infiltrate a filter. Wetting in the Al-Al2O3 system increases with temperature.

  3. Analysis of differentially expressed genes between fluoride-sensitive and fluoride-endurable individuals in midgut of silkworm, Bombyx mori.

    Science.gov (United States)

    Qian, Heying; Li, Gang; He, Qingling; Zhang, Huaguang; Xu, Anying

    2016-08-15

    Fluoride tolerance is an economically important trait of silkworm. Near-isogenic lines (NILs) of the dominant endurance to fluoride (Def) gene in Bombyx mori has been constructed before. Here, we analyzed the gene expression profiles of midgut of fluoride-sensitive and fluoride-endurable individuals of Def NILs by using high-throughput Illumina sequencing technology and bioinformatics tools, and identified differentially expressed genes between these individuals. A total of 3,612,399 and 3,567,631 clean tags for the libraries of fluoride-endurable and fluoride-sensitive individuals were obtained, which corresponded to 32,933 and 43,976 distinct clean tags, respectively. Analysis of differentially expressed genes indicates that 241 genes are differentially expressed between the two libraries. Among the 241 genes, 30 are up-regulated and 211 are down-regulated in fluoride-endurable individuals. Pathway enrichment analysis demonstrates that genes related to ribosomes, pancreatic secretion, steroid biosynthesis, glutathione metabolism, steroid biosynthesis, and glycerolipid metabolism are down-regulated in fluoride-endurable individuals. qRT-PCR was conducted to confirm the results of the DGE. The present study analyzed differential expression of related genes and tried to find out whether the crucial genes were related to fluoride detoxification which might elucidate fluoride effect and provide a new way in the fluorosis research.

  4. Fluoride ion encapsulation by Mg[superscript 2+] ions and phosphates in a fluoride riboswitch

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Aiming; Rajashankar, Kanagalaghatta R.; Patel, Dinshaw J. (Cornell); (MSKCC)

    2012-06-26

    Significant advances in our understanding of RNA architecture, folding and recognition have emerged from structure-function studies on riboswitches, non-coding RNAs whose sensing domains bind small ligands and whose adjacent expression platforms contain RNA elements involved in the control of gene regulation. We now report on the ligand-bound structure of the Thermotoga petrophila fluoride riboswitch, which adopts a higher-order RNA architecture stabilized by pseudoknot and long-range reversed Watson-Crick and Hoogsteen A {sm_bullet} U pair formation. The bound fluoride ion is encapsulated within the junctional architecture, anchored in place through direct coordination to three Mg{sup 2+} ions, which in turn are octahedrally coordinated to water molecules and five inwardly pointing backbone phosphates. Our structure of the fluoride riboswitch in the bound state shows how RNA can form a binding pocket selective for fluoride, while discriminating against larger halide ions. The T. petrophila fluoride riboswitch probably functions in gene regulation through a transcription termination mechanism.

  5. Fluoride ion encapsulation by Mg2+ ions and phosphates in a fluoride riboswitch.

    Science.gov (United States)

    Ren, Aiming; Rajashankar, Kanagalaghatta R; Patel, Dinshaw J

    2012-05-13

    Significant advances in our understanding of RNA architecture, folding and recognition have emerged from structure-function studies on riboswitches, non-coding RNAs whose sensing domains bind small ligands and whose adjacent expression platforms contain RNA elements involved in the control of gene regulation. We now report on the ligand-bound structure of the Thermotoga petrophila fluoride riboswitch, which adopts a higher-order RNA architecture stabilized by pseudoknot and long-range reversed Watson-Crick and Hoogsteen A•U pair formation. The bound fluoride ion is encapsulated within the junctional architecture, anchored in place through direct coordination to three Mg(2+) ions, which in turn are octahedrally coordinated to water molecules and five inwardly pointing backbone phosphates. Our structure of the fluoride riboswitch in the bound state shows how RNA can form a binding pocket selective for fluoride, while discriminating against larger halide ions. The T. petrophila fluoride riboswitch probably functions in gene regulation through a transcription termination mechanism.

  6. The Effect of Calcium Pre-Rinse on Salivary Fluoride After 900 ppm Fluoride Mouthwash: A Randomized Clinical Trial

    Directory of Open Access Journals (Sweden)

    Nahid Ramazani

    2013-01-01

    Full Text Available Objective: Calcium fluoride deposit during fluoride application. Uptake and retention of fluoride by saliva depends generally on the concentration of calcium. In this study, the ef-fect of calcium pre-rinse on salivary fluoride concentration after a 900 ppm fluoride mouthwash was investigated.Materials and Methods: This cross-over double-blind randomized clinical trial was con-ducted in a girls' dormitory in Zahedan University of Medical Sciences, southeast Iran. In this study, 42 female dental students were chosen using simple randomization. During the first phase, 21 subjects (group A used fluoride rinse (F regimen and the remaining (group B used calcium pre-rinse followed immediately by fluoride rinse (Ca + F regi-men. In the second phase, participants rinsed using the mouthwashes not previously used. Prior to each phase prophylaxis was performed and no fluoridated product was used dur-ing a two-week interval between the phases. Salivary samples were taken immediately be-fore (baseline, 1 and 12 hours after rinsing. The salivary fluoride concentration was de-termined using fluoride sensitive electrode. Repeated measures ANOVA was used for sta-tistical analysis and the significance level was set at P<0.05.Results: There was significant difference between fluoride concentrations at different time points (P< 0.001. Significant differences were observed when the different time points of two regimens were examined. In contrast to this, the baseline before using F regimen and the baseline before using Ca + F regimen did not show any significance (P= 0.070.Conclusion: Pre-rinsing with calcium before fluoride is recommended because of signifi-cant increases in salivary fluoride concentration.

  7. Sodium in feline nutrition.

    Science.gov (United States)

    Nguyen, P; Reynolds, B; Zentek, J; Paßlack, N; Leray, V

    2016-08-23

    High sodium levels in cat food have been controversial for a long time. Nonetheless, high sodium levels are used to enhance water intake and urine volume, with the main objective of reducing the risk of urolithiasis. This article is a review of current evidence of the putative risks and benefits of high dietary sodium levels. Its secondary aim is to report a possible safe upper limit (SUL) for sodium intake. The first part of the manuscript is dedicated to sodium physiology, with a focus on the mechanisms of sodium homeostasis. In this respect, there is only few information regarding possible interactions with other minerals. Next, the authors address how sodium intake affects sodium balance; knowledge of these effects is critical to establish recommendations for sodium feed content. The authors then review the consequences of changes in sodium intake on feline health, including urolithiasis, blood pressure changes, cardiovascular alterations and kidney disease. According to recent, long-term studies, there is no evidence of any deleterious effect of dietary sodium levels as high as 740 mg/MJ metabolizable energy, which can therefore be considered the SUL based on current knowledge.

  8. Remaining phosphorus and sodium fluoride pH in soils with different clay contents and clay mineralogies Fósforo remanescente e pH em fluoreto de sódio em solos com diferentes teores e qualidades de argila

    Directory of Open Access Journals (Sweden)

    Marcelo Eduardo Alves

    2004-03-01

    Full Text Available The remaining phosphorus (Prem has been used for estimating the phosphorus buffer capacity (PBC of soils of some Brazilian regions. Furthermore, the remaining phosphorus can also be used for estimating P, S and Zn soil critical levels determined with PBC-sensible extractants and for defining P and S levels to be used not only in P and S adsorption studies but also for the establishment of P and S response curves. The objective of this work was to evaluate the effects of soil clay content and clay mineralogy on Prem and its relationship with pH values measured in saturated NaF solution (pH NaF. Ammonium-oxalate-extractable aluminum exerts the major impacts on both Prem and pH NaF, which, in turn, are less dependent on soil clay content. Although Prem and pH NaF have consistent correlation, the former has a soil-PBC discriminatory capacity much greater than pH NaF.O fósforo remanescente (Prem tem sido utilizado para estimar o fator capacidade de P (FCP de solos de algumas regiões do Brasil. Entre outras finalidades, o P remanescente pode também ser utilizado para estimar níveis críticos de P, S e Zn no solo, determinados com extratores sensíveis ao FCP, e para a definição das doses de P e S a serem usadas, tanto em estudos de adsorção como no estabelecimento de curvas de resposta a esses elementos. O objetivo deste trabalho foi avaliar os efeitos do teor e da composição mineralógica da fração argila do solo sobre o Prem, e sua relação com o pH medido em solução saturada de NaF (pH NaF. Tanto o Prem quanto o pH NaF são mais influenciados pelo teor de Al extraído com oxalato de amônio e menos dependentes do teor de argila. Embora a correlação entre o Prem e o pH NaF seja consistente, o Prem apresenta maior capacidade de estratificar solos quanto ao fator capacidade de fósforo que o pH NaF.

  9. Revisiting the thermochemistry of chlorine fluorides

    CERN Document Server

    Sánchez, H R

    2016-01-01

    In this work, accurate calculations of standard enthalpies of formation of chlorine fluorides (ClF$_n$, n=1--7; Cl$_2$F and Cl$_3$F$_2$) were performed through the isodesmic reactions scheme. It is argued that, for many chlorine fluorides, the gold standard method of quantum chemistry (CCSD(T)) is not capable to predict enthalpy values nearing chemical accuracy if atomization scheme is used. This is underpinned by a thorough analysis of total atomization energy results and the inspection of multireference features of these compounds. Other thermodynamic quantities were also calculated at different temperatures. In order to complement the energetic description, elimination curves were studied through density functional theory as a computationally affordable alternative to highly correlated wave function-based methods.

  10. Fluoridation and tooth wear in Irish adults.

    LENUS (Irish Health Repository)

    Burke, F M

    2010-10-01

    The aim of this study was to determine the prevalence of tooth wear in adults in Ireland and its relationship with water fluoridation. The National Survey of Adult Oral Health was conducted in 2000\\/2001. Tooth wear was determined using a partial mouth examination assessing the upper and lower anterior teeth. A total of 2456 subjects were examined. In this survey, increasing levels and severity of tooth wear were associated with ageing. Men were more affected by tooth wear and were more likely to be affected by severe tooth wear than women. It was found that age, and gender were significant predictors of tooth wear (P < 0.01). Overall, there was no significant relationship between fluoridation and tooth wear in this study.

  11. Fluoride complexation of element 104, rutherfordium.

    Science.gov (United States)

    Haba, Hiromitsu; Tsukada, Kazuaki; Asai, Masato; Toyoshima, Atsushi; Akiyama, Kazuhiko; Nishinaka, Ichiro; Hirata, Masaru; Yaita, Tsuyoshi; Ichikawa, Shin-Ichi; Nagame, Yuichiro; Yasuda, Ken-Ichiro; Miyamoto, Yutaka; Kaneko, Tetsuya; Goto, Shin-Ichi; Ono, Sawako; Hirai, Toshiyuki; Kudo, Hisaaki; Shigekawa, Mitsuru; Shinohara, Atsushi; Oura, Yasuji; Nakahara, Hiromichi; Sueki, Keisuke; Kikunaga, Hidetoshi; Kinoshita, Norikazu; Tsuruga, Naoya; Yokoyama, Akihiko; Sakama, Minoru; Enomoto, Shuich; Schädel, Matthias; Brüchle, Willy; Kratz, Jens V

    2004-04-28

    Fluoride complexation of element 104, rutherfordium (Rf), produced in the 248Cm(18O,5n)261Rf reaction has been studied by anion-exchange chromatography on an atom-at-a-time scale. The anion-exchange chromatographic behavior of Rf was investigated in 1.9-13.9 M hydrofluoric acid together with those of the group-4 elements Zr and Hf produced in the 18O-induced reactions on Ge and Gd targets, respectively. It was found that the adsorption behavior of Rf on anion-exchange resin is quite different from those of Zr and Hf, suggesting the influence of relativistic effects on the fluoride complexation of Rf.

  12. Necessity to review the Brazilian regulation about fluoride toothpastes.

    Science.gov (United States)

    Cury, Jaime Aparecido; Caldarelli, Pablo Guilherme; Tenuta, Livia Maria Andaló

    2015-01-01

    The aim of this study was to evaluate the adequacy of the Brazilian legislation about fluoride toothpaste. A search was conducted in LILACS, Medline and SciELO databases about the fluoride concentration found in Brazilians toothpastes, using descriptors on health. Publications since 1981 have shown that some Brazilian toothpastes are not able to maintain, during their expiration time, a minimum of 1,000 ppm F of soluble fluoride in the formulation. However, the Brazilian regulation (ANVISA, Resolution 79, August 28, 2000) only sets the maximum total fluoride (0.15%; 1,500 ppm F) that a toothpaste may contain but not the minimum concentration of soluble fluoride that it should contain to have anticaries potential, which according to systematic reviews should be 1,000 ppm F. Therefore, the Brazilian regulation on fluoride toothpastes needs to be revised to assure the efficacy of those products for caries control.

  13. Bone fluoride concentrations in beluga whales from Canada.

    Science.gov (United States)

    Mikaelian, I; Qualls, C W; De Guise, S; Whaley, M W; Martineau, D

    1999-04-01

    Beluga whales (Delphinapterus leucas) from the St. Lawrence Estuary have been reported to have dental and bone abnormalities. To determine whether these lesions could be caused by high exposure to fluorides, we measured bone fluoride levels in eight beluga whales stranded on the shores of the St. Lawrence Estuary (Quebec, Canada), and in nine beluga whales killed by Inuit hunters in the Hudson Bay (North Western Territories, Canada). In both groups, fluoride concentrations were higher than those found in terrestrial mammals intoxicated by fluorides. Unexpectedly, fluoride concentration was significantly higher in beluga whales from the Hudson Bay (mean +/- SD: 10.365 +/- 1.098 ppm) than in beluga whales from the St. Lawrence Estuary (4.539 +/- 875 ppm) and was positively correlated with age in the latter population. Differences in diet might explain the differences in fluoride concentrations found between these two populations.

  14. Adsorption of Fluoride Ion by Inorganic Cerium Based Adsorbent

    Institute of Scientific and Technical Information of China (English)

    Jiao Zhongzhi(焦中志); Chen Zhonglin; Yang Min; Zhang Yu; Li Guibai

    2004-01-01

    Excess of fluoride in drinking water is harmful to human health, the concentration of F- ions must be maintained in the range of 0.5 to 1.5 mg/L. An inorganic cerium based adsorbent (CTA) is developed on the basis of research of adsorption of fluoride on cerium oxide hydrate. Some adsorption of fluoride by CTA adsorbent experiments were carried out, and results showed that CTA adsorbent has a quick adsorption speed and a large adsorption capacity. Adsorption follows Freundlich isotherm, and low pH value helps fluoride removal. Some physical-chemical characteristics of CTA adsorbent were experimented, fluoride removal mechanism was explored, and results showed that hydroxyl group of CTA adsorbent played an important role in the fluoride removal.

  15. Fluoride contamination in rain water of Sigrauli region

    Energy Technology Data Exchange (ETDEWEB)

    Chaurasia, S.; Mishra, S.K. [Mahatma Gandhi Chitrakoot Gramodaya, Chitrakoot (India)

    2007-07-01

    In this paper fluoride was monitored in rain water during rainy season at seven locations of Sigrauli region in 2004. The sampling location covered the impact of industrial complex of the area, and its impact on surface water sources monitored for the fluoride, pH, and electrical conductivity. The higher concentration of fluoride in rain water was observed 2.03 mg/L at Dudhar and in ponds water highest value was 3.14 mg/L. This suggested that serious fluoride pollution is occurring in Singrauli region posing a threat to the health and livelihood of the people of the region. Fluoride transported by the air route from coal burning emissions of large thermal power plants concentrate in small geographical area, and industries. Fluoride pollution in Singrauli area deserve intensive scientific studies and urgent attention. 2 figs., 2 tabs.

  16. Viscosity estimation for slags containing calcium fluoride

    Institute of Scientific and Technical Information of China (English)

    Qifeng Shu; Jiayun Zhang

    2005-01-01

    Based on recently published experimental data, the Riboud model was modified for viscosity estimation of the slags containing calcium fluoride. The estimated values were in good agreement with measured data. Reasonable estimation can be achieved using the modified Riboud model for mould fluxes and ESR (eletro slag remelting) slags. Especially for ESR slags, the modified Riboud model can provide much more precise values than the original Riboud model.

  17. Fluoride glasses: properties, technology and applications

    OpenAIRE

    Poulain, M.

    2010-01-01

    Heavy Metal Fluoride Glasses (HMFG) make a group of specialty glasses that require a dry processing, purity control of starting materials and specific thermal procedures. Numerous glass compositions have been identified in different chemical systems: fluorozirconates, fluoroaluminates and fluoroindates. The most commonly used HMFG is the ZBLAN fluorozirconate glass that exhibits the largest stability against devitrification. By comparison to ZBLAN the IR cut-off wavelength is shorter in AlF3-...

  18. Hualu Aluminum Will Construct Large Coal-Power-Aluminum Aluminum Processing Industrial Chain

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    The reporter learned from relevant departments of Baiyin City that in order to further push forward industrial upgrading,fulfill expansion and consolidation of the enterprise,Gansu Hualu Aluminum Co.,Ltd(Hualu Aluminum)will implement Out-Of-City-Into-Park project,

  19. Reduction in fluoride-induced genotoxicity in mouse bone marrow cells after substituting high fluoride-containing water with safe drinking water.

    Science.gov (United States)

    Podder, Santosh; Chattopadhyay, Ansuman; Bhattacharya, Shelley

    2011-10-01

    Treatment of mice with 15 mg l(-1) sodium fluoride (NaF) for 30 days increased the number of cell death, chromosomal aberrations (CAs) and 'cells with chromatid breaks' (aberrant cells) compared with control. The present study was intended to determine whether the fluoride (F)-induced genotoxicity could be reduced by substituting high F-containing water after 30 days with safe drinking water, containing 0.1 mg F ions l(-1). A significant fall in percentage of CAs and aberrant cells after withdrawal of F-treatment following 30 days of safe water treatment in mice was observed which was highest after 90 days, although their levels still remained significantly high compared with the control group. This observation suggests that F-induced genotoxicity could be reduced by substituting high F-containing water with safe drinking water. Further study is warranted with different doses and extended treatment of safe water to determine whether the induced damages could be completely reduced or not.

  20. Color stability of esthetic restorative material after topical fluoride application

    OpenAIRE

    2015-01-01

    AIM: Present study was conducted to compare the effect of topical fluoride agents on color change of three aesthetic restorative materials. MATERIAL AND METHODS: Restorative material used were Ketac Fill type II (GIC), Filtek Z350(Composite) and Beuttifull II (Giomer). Topical Fluorides used were Pascal (1.23% APF gel) and Fluoride Varnish (Bifluoride). 24 samples of each restorative material were prepared, which were divided into 8 each, among three groups. Treatment of Group A with APF gel,...

  1. Inhibition of dentin demineralization by fluoride in vitro.

    Science.gov (United States)

    ten Cate, J M; Damen, J J; Buijs, M J

    1998-01-01

    Compared with the knowledge accumulated on enamel-fluoride interactions, relatively little data is available regarding fluoride effects on dentin. This applies to both laboratory and clinical studies into the efficacy of fluoride schemes for the prevention of root surface caries. This study aimed to determine the effects of fluoride and pH on the demineralization of dentin, such as to provide information necessary to develop preventive programmes. Bovine dentin blocks were subjected to undersaturated calcium- and phosphate-containing solutions in the pH range 4.0-6.0 with fluoride added at concentrations between 0.5 and 10 ppm. Non-fluoride solutions served as controls. Mineral loss was assessed chemically and by transversal microradiography. Comparisons were made with similar studies on enamel demineralization. The results showed that demineralization of dentin depends on both pH and fluoride concentration in the demineralizing solution. Inhibition of demineralization that could be relevant from a clinical point of view was found at fluoride values 5-10 times the corresponding values for enamel. Also rapid depletion of fluoride from the solutions was observed, indicating the high uptake capacity of dentin for fluoride. Lesion depth depended on pH of the solution while the fluoride levels were associated with the surface layer, both in mineral content and depth. For dentin we propose a demineralization mechanism where acid penetrates rapidly into the tissue, presumably through the tubules, after which the released calcium and phosphate is partly trapped by the inward diffusing fluoride. This leads to the formation of a surface layer, which may even be hypermineralized compared to sound dentin.

  2. Studies on fluoride complexing of hexavalent actinides using a fluoride ion selective electrode

    Energy Technology Data Exchange (ETDEWEB)

    Sawant, R.M.; Chaudhuri, N.K.; Rizvi, G.H.; Patil, S.K.

    1985-08-01

    Complex formation between actinide(VI) and fluoride ions in aqueous solutions was investigated using a fluoride ion selective electrode (F-ISE). As fairly high acidity used to suppress hydrolysis of the actinide(VI) ions, significant liquid junction potentials (Esub(j)) existed in the system. An iterative procedure was developed for computing free hydrogen ion concentration (Hsup(+)) as it could not be measured directly, using data obtained with F-ISE. Esub(j) values were estimated from known (Hsup(+)) and the stability constants of fluoride complexes of actinide(VI) ions were calculated following King and Gallagher's method using a computer program. The stability constants were found to follow the order U(VI) > Np(VI) > Pu(VI). (author). 18 refs.; 3 figs.; 9 tables.

  3. Reviews of the environmental effects of pollutants. IX. Fluoride

    Energy Technology Data Exchange (ETDEWEB)

    Drury, J.S.; Ensminger, J.T.; Hammons, A.S.; Holleman, J.W.; Lewis, E.B.; Preston, E.L.; Shriner, C.R.; Towill, L.E.

    1980-09-01

    This study is a comprehensive, multidisciplinary review of the health and environmental effects of fluoride on microorganisms, plants, wild and domestic animals, and humans. More than 1000 references are cited. Human intake of fluoride is chiefly through the diet; drinking water is normally the largest single source. Low concentrations of fluoride in water (approximately 1 ppM) benefit mammalian systems, making bone and tooth apatite less soluble, but long-term ingestion of water containing more than 8 ppM fluoride causes fluorosis in humans. Fluoride salts are lethal to humans when ingested in doses of about 3 g or more. At concentrations normally encountered by the general public, fluoride is not teratogenic, mutagenic, or carcinogenic to humans, but chronic fluoride toxicosis of both livestock and wildlife is an important problem in many areas of the United States. The principal manifestations of chronic fluoride toxicosis in livestock are dental fluorosis, osteofluorosis, lameness, and impaired performance. Among domestic animals, dairy cattle are the most sensitive to excessive fluoride exposure.

  4. Fluoride content in caffeinated, decaffeinated and herbal teas.

    Science.gov (United States)

    Chan, J T; Koh, S H

    1996-01-01

    The fluoride contents of infusions prepared from 44 different brands and types of teas were measured. Fluoride concentrations ranged from 0.34 to 3.71 ppm (mean = 1.50 ppm) in caffeinated tea infusions, 0.02-0.14 ppm (mean = 0.05 ppm) in herbal tea infusions, and 1.01-5.20 ppm (mean = 3.19) in decaffeinated tea infusions. This is the first report of the fluoride content of decaffeinated teas. The mean fluoride content of decaffeinated tea infusions is significantly (p decaffeination is the most likely explanation of the above observation.

  5. LiFePO_4/C via fluoride doping

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Non-stoichiometric compound fluoride-doped LiFePO4/C cathode materials were synthesized via solid-state reaction using MgF2 and AlF3 as dopant. The fluoride-doped LiFePO4/C samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and electrochemical testing. The results show that the materials are well crystallized and fluoride doping cannot change the space structure of LiFePO4. Slight amounts of Fe2O3 with no fluoride impurity were ...

  6. Cerebrospinal fluid sodium rhythms

    Directory of Open Access Journals (Sweden)

    Johnson Benjamin

    2010-01-01

    Full Text Available Abstract Background Cerebrospinal fluid (CSF sodium levels have been reported to rise during episodic migraine. Since migraine frequently starts in early morning or late afternoon, we hypothesized that natural sodium chronobiology may predispose susceptible persons when extracellular CSF sodium increases. Since no mammalian brain sodium rhythms are known, we designed a study of healthy humans to test if cation rhythms exist in CSF. Methods Lumbar CSF was collected every ten minutes at 0.1 mL/min for 24 h from six healthy participants. CSF sodium and potassium concentrations were measured by ion chromatography, total protein by fluorescent spectrometry, and osmolarity by freezing point depression. We analyzed cation and protein distributions over the 24 h period and spectral and permutation tests to identify significant rhythms. We applied the False Discovery Rate method to adjust significance levels for multiple tests and Spearman correlations to compare sodium fluctuations with potassium, protein, and osmolarity. Results The distribution of sodium varied much more than potassium, and there were statistically significant rhythms at 12 and 1.65 h periods. Curve fitting to the average time course of the mean sodium of all six subjects revealed the lowest sodium levels at 03.20 h and highest at 08.00 h, a second nadir at 09.50 h and a second peak at 18.10 h. Sodium levels were not correlated with potassium or protein concentration, or with osmolarity. Conclusion These CSF rhythms are the first reports of sodium chronobiology in the human nervous system. The results are consistent with our hypothesis that rising levels of extracellular sodium may contribute to the timing of migraine onset. The physiological importance of sodium in the nervous system suggests that these rhythms may have additional repercussions on ultradian functions.

  7. Effect of bariun on the refinement of primary aluminum and eutectics in a hypoeutectic Al-Si alloy

    Institute of Scientific and Technical Information of China (English)

    LI Wei; FAN Hongyuan; ZHANG Xianju; SHEN Baoluo

    2003-01-01

    The effect of barium on the refinement of primary aluminum and on the modification of eutectics in a hypoeutectic aluminm-silicon alloy was investigated. The results indicate that barium not only modifies the eutectic silicon but also refines the primary aluminum and there is a relationship between the retained barium and the second spacing of primary aluminum. Experiments of barium-treated commercial Al-Si hypoeutectic alloy show that barium is a better modifier than sodium when there is a longer holding time.

  8. Spray Rolling Aluminum Strip

    Energy Technology Data Exchange (ETDEWEB)

    Lavernia, E.J.; Delplanque, J-P; McHugh, K.M.

    2006-05-10

    Spray forming is a competitive low-cost alternative to ingot metallurgy for manufacturing ferrous and non-ferrous alloy shapes. It produces materials with a reduced number of processing steps, while maintaining materials properties, with the possibility of near-net-shape manufacturing. However, there are several hurdles to large-scale commercial adoption of spray forming: 1) ensuring strip is consistently flat, 2) eliminating porosity, particularly at the deposit/substrate interface, and 3) improving material yield. Through this program, a new strip/sheet casting process, termed spray rolling, has been developed, which is an innovative manufacturing technique to produce aluminum net-shape products. Spray rolling combines the benefits of twin-roll casting and conventional spray forming, showing a promising potential to overcome the above hurdles associated with spray forming. Spray rolling requires less energy and generates less scrap than conventional processes and, consequently, enables the development of materials with lower environmental impacts in both processing and final products. Spray Rolling was developed as a collaborative project between the University of California-Davis, the Colorado School of Mines, the Idaho National Engineering and Environmental Laboratory, and an industry team. The following objectives of this project were achieved: (1) Demonstration of the feasibility of the spray rolling process at the bench-scale level and evaluation of the materials properties of spray rolled aluminum strip alloys; and (2) Demonstration of 2X scalability of the process and documentation of technical hurdles to further scale up and initiate technology transfer to industry for eventual commercialization of the process.

  9. TANK 12 SLUDGE CHARACTERIZATION AND ALUMINUM DISSOLUTION DEMONSTRATION

    Energy Technology Data Exchange (ETDEWEB)

    Reboul, S; Michael Hay, M; Kristine Zeigler, K; Michael Stone, M

    2009-03-25

    A 3-L sludge slurry sample from Tank 12 was characterized and then processed through an aluminum dissolution demonstration. The dominant constituent of the sludge was found to be aluminum in the form of boehmite. The iron content was minor, about one-tenth that of the aluminum. The salt content of the supernatant was relatively high, with a sodium concentration of {approx}7 M. Due to these characteristics, the yield stress and plastic viscosity of the unprocessed slurry were relatively high (19 Pa and 27 cP), and the settling rate of the sludge was relatively low ({approx}20% settling over a two and a half week period). Prior to performing aluminum dissolution, plutonium and gadolinium were added to the slurry to simulate receipt of plutonium waste from H-Canyon. Aluminum dissolution was performed over a 26 day period at a temperature of 65 C. Approximately 60% of the insoluble aluminum dissolved during the demonstration, with the rate of dissolution slowing significantly by the end of the demonstration period. In contrast, approximately 20% of the plutonium and less than 1% of the gadolinium partitioned to the liquid phase. However, about a third of the liquid phase plutonium became solubilized prior to the dissolution period, when the H-Canyon plutonium/gadolinium simulant was added to the Tank 12 slurry. Quantification of iron dissolution was less clear, but appeared to be on the order of 1% based on the majority of data (a minor portion of the data suggested iron dissolution could be as high as 10%). The yield stress of the post-dissolution slurry (2.5 Pa) was an order of magnitude lower than the initial slurry, due most likely to the reduced insoluble solids content caused by aluminum dissolution. In contrast, the plastic viscosity remained unchanged (27 cP). The settling rate of the post-dissolution slurry was higher than the initial slurry, but still relatively low compared to settling of typical high iron content/low salt content sludges. Approximately 40

  10. Tank 12 Sludge Characterization and Aluminum Dissolution Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Reboul, S.; Hay, M.; Zeigler, K; Stone, M.

    2010-05-05

    A 3-L sludge slurry sample from Tank 12 was characterized and then processed through an aluminum dissolution demonstration. The dominant constituent of the sludge was found to be aluminum in the form of boehmite. The iron content was minor, about one-tenth that of the aluminum. The salt content of the supernatant was relatively high, with a sodium concentration of {approx}7 M. Due to these characteristics, the yield stress and plastic viscosity of the unprocessed slurry were relatively high (19 Pa and 27 cP), and the settling rate of the sludge was relatively low ({approx}20% settling over a two and a half week period). Prior to performing aluminum dissolution, plutonium and gadolinium were added to the slurry to simulate receipt of plutonium waste from H-Canyon. Aluminum dissolution was performed over a 26 day period at a temperature of 65 C. Approximately 60% of the insoluble aluminum dissolved during the demonstration, with the rate of dissolution slowing significantly by the end of the demonstration period. In contrast, approximately 20% of the plutonium and less than 1% of the gadolinium partitioned to the liquid phase. However, about a third of the liquid phase plutonium became solubilized prior to the dissolution period, when the H-Canyon plutonium/gadolinium simulant was added to the Tank 12 slurry. Quantification of iron dissolution was less clear, but appeared to be on the order of 1% based on the majority of data (a minor portion of the data suggested iron dissolution could be as high as 10%). The yield stress of the post-dissolution slurry (2.5 Pa) was an order of magnitude lower than the initial slurry, due most likely to the reduced insoluble solids content caused by aluminum dissolution. In contrast, the plastic viscosity remained unchanged (27 cP). The settling rate of the post-dissolution slurry was higher than the initial slurry, but still relatively low compared to settling of typical high iron content/low salt content sludges. Approximately 40

  11. Subsurface Aluminum Nitride Formation in Iron-Aluminum Alloys

    Science.gov (United States)

    Bott, June H.

    Transformation-induced plasticity (TRIP) steels containing higher amounts of aluminum than conventional steels are ideal for structural automotive parts due to their mechanical properties. However, the aluminum tends to react with any processing environment at high temperatures and therefore presents significant challenges during manufacturing. One such challenge occurs during secondary cooling, reheating, and hot-rolling and is caused by a reaction with nitrogen-rich atmospheres wherein subsurface aluminum nitride forms in addition to internal and external oxides. The nitrides are detrimental to mechanical properties and cause surface cracks. It is important to understand how these nitrides and oxides form and their consequences for the quality of steel products. This study looks at model iron-aluminum (up to 8 wt.% aluminum) alloys and uses confocal laser scanning microscopy, x-ray diffraction, scanning electron microscopy with energy dispersive x-ray spectrometry, and transmission electron microscopy to study the effect of various conditions on the growth and development of these precipitates in a subsurface oxygen-depleted region. By using model alloys and controlling the experimental atmosphere, this study is able to understand some of the more fundamental materials science behind aluminum nitride formation in aluminum-rich iron alloys and the relationship between internal nitride and oxide precipitation and external oxide scale morphology and composition. The iron-aluminum alloys were heated in N2 atmospheres containing oxygen impurities. It was found that nitrides formed when bulk aluminum content was below 8 wt.% when oxygen was sufficiently depleted due to the internal oxidation. In the samples containing 1 wt.% aluminum, the depth of the internal oxide and nitride zones were in agreement with a diffusion-based model. Increasing aluminum content to 3 and 5 wt% had the effects of modifying the surface-oxide scale composition and increasing its continuity

  12. Preparation of Scandium-Bearing Master Alloys by Aluminum-Magnesium Thermoreduction

    Institute of Scientific and Technical Information of China (English)

    姜锋; 白兰; 尹志民

    2002-01-01

    The new preparation method of scandium-bearing master alloys, in which scandium oxide was fluorinated by reaction with NH4HF2 and then reduced by aluminum-magnesium in fused salt containing alkali and alkaline fluoride under atmosphere, was studied. The effect of sorts of metallic reductive and technique conditions such as reducing temperature and time on the recovery of Sc was discussed. When the liquid aluminum-magnesium was used as the reductive agent, the all-recovery exceeds 80% and the concentration of Sc in master alloy prepared exceeds 1.9%. The best reducing reaction temperature and time are 1100 K and 40 min respectively. The newly produced Sc from reduction combines with Al to produce the stable compound Al3Sc, so the reduction progress is sustained and the recovery of Sc is increased.

  13. Equation of state of aluminum-iron oxide-epoxy composite

    Science.gov (United States)

    Jordan, Jennifer L.; Ferranti, Louis; Austin, Ryan A.; Dick, Richard D.; Foley, Jason R.; Thadhani, Naresh N.; McDowell, David L.; Benson, David J.

    2007-05-01

    We report on the measurements of the shock equation of state (Hugoniot) of an Al/Fe2O3/epoxy composite, prepared by epoxy cast curing of powder mixtures. Explosive loading, with Baratol, trinitrotoluene (TNT), and Octol, was used for performing experiments at higher pressures, in which case shock velocities were measured in the samples and aluminum, copper, or polymethyl methacrylate (PMMA) donor material, using piezoelectric pins. The explosive loading of the metal donors (aluminum and copper) will be discussed. Gas gun experiments provide complementary lower pressure data in which piezoelectric polyvinylidene fluoride (PVDF) stress gauges were used to measure the input and propagated stress wave profiles in the sample and the corresponding shock propagation velocity. The results of the Hugoniot equation of state are compared with mesoscale finite-element simulations, which show good agreement.

  14. Determination of Fluoride in Toothpaste Using an Ion-Selective Electrode

    Science.gov (United States)

    Light, Truman S.; Cappuccino, Carleton C.

    1975-01-01

    Outlines the theory of chemical potentiometry, describes the experimental procedure for free fluoride determination, and presents sample data of fluoride concentration for various brands of toothpaste. (GS)

  15. The influence of sodium nanoparticles formation on luminescent properties of fluorophosphate glasses containing molecular clusters and quantum dots of lead selenide

    Science.gov (United States)

    Lipatova, Zh. O.; Kolobkova, E. V.; Sidorov, A. I.; Nikonorov, N. V.

    2016-08-01

    The influence of sodium nanoparticles and secondary heat treatment conditions on the spectralluminescent characteristics of fluorophosphate glasses with PbSe molecular clusters and quantum dots is studied. Experiments with glasses containing no sodium nanoparticles show that their thermal treatment leads to the formation of molecular clusters with subsequent formation of quantum dots having an intense luminescence. The results of numerical simulation for glasses with sodium nanoparticles shows that heat treatment leads to formation of a sodium fluoride shell on the nanoparticles surface. It is shown that quenching of the luminescence of PbSe molecular clusters and quantum dots takes place in these glasses.

  16. PREPARATION AND CHARACTERIZATION OF STRONTIUM FLUORIDE POWDERS ACTIVATED BY NEODYMIUM FLUORIDE

    Directory of Open Access Journals (Sweden)

    S. V. Kuznetsov

    2015-07-01

    Full Text Available Subject of Study. The paper deals with preparation processes of ultradisperse, homogeneous powder Sr1-хNdхF2+х (х= 0.003-0.2, with use of ammonium fluoride as the fluorinating agent taken over 114-120 % from stoichiometry. Method. Nitrate of strontium, neodymium nitrate hexahydrate, with the content equal to 99. 99 % of the basic substance and ammonium fluoride were used as the source of substances. Activated powders of strontium fluoride were obtained by the method of deposition from aqueous solutions by washing the precipitate with a solution of ammonium fluoride, taken over 114 - 120% from stoichiometry. The washed precipitate was centrifuged for 5-7 min, dried in the air at 30-350 C. Heat treatment of the dried precipitate was carried out in two stages: the first stage at the temperature of 200- 2500 C for 0.5-1 hour, the second one at 550- 6000 C for 2-3 hours. X-ray analysis of the synthesized samples was carried out on a Bruker D8 Advance diffractometer, radiation Cu K. The size and shape measuring of the particles of activated strontium fluoride was carried out by means of electron microscope Carl Zeiss NVision 40. The content of neodymium in activated powders of strontium fluoride was determined by the method of spectral emission analysis on the device LEA - S500. Chemical analysis for determination of ammonium ion (NH4+ content in the obtained samples was performed by the method of Kjeldahl. Calculations of lattice parameters, size of coherent scattering regions and the values of micro-deformations were carried out by TOPAS program. Main Results. Preparation processes of ultradisperse, homogeneous powder Sr1-хNdхF2+х (х= 0.003-0.2, with use of ammonium fluoride as the fluorinating agent taken over 114-120 % from stoichiometry, provides obtaining the firm solution Sr1-x-yNdx(NH4yF2+x-y of the cubic fluorite structure. It has been found out that the morphology and size of the resulting product depend on the quantity of

  17. Solubilities of sodium nitrate, sodium nitrite, and sodium aluminate in simulated nuclear waste

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, D.A.; Herting, D.L.

    1984-09-01

    Solubilities were determined for sodium nitrate, sodium nitrite, and sodium aluminate in synthetic nuclear waste liquor. Solubilities were determined as a function of temperature and solution composition (concentrations of sodium hydroxide, sodium nitrate, sodium nitrite, and sodium aluminate). Temperature had the greatest effect on the solubilities of sodium nitrate and sodium nitrite and a somewhat lesser effect on sodium aluminate solubility. Hydroxide had a great effect on the solubilities of all three salts. Other solution components had minor effects. 2 references, 8 figures, 11 tables.

  18. Aluminum-rich mesoporous MFI - type zeolite single crystals

    DEFF Research Database (Denmark)

    Kustova, Marina; Kustov, Arkadii; Christensen, Christina Hviid

    2005-01-01

    Zeolitcs are crystalline materials, which are widely used as solid acid catalysts and supports in many industrial processes. Recently, mesoporous MFI-type zeolite single crystals were synthesized by use of carbon particles as a mesopore template and sodium aluminate as the aluminum Source...... are characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), ammonia temperature programmed desorption (NH3-TPD), and N-2 adsorption measurements. The obtained zeolites combine the high crystallinity and the characteristic micropores of zeolites with an intracrystalline mesopore system...

  19. Scientific Opinion on Dietary Reference Values for fluoride

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA

    2013-08-01

    Full Text Available Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies (NDA derived Dietary Reference Values (DRVs for fluoride, which are provided as Adequate Intake (AI from all sources, including non-dietary sources. Fluoride is not an essential nutrient. Therefore, no Average Requirement for the performance of essential physiological functions can be defined. Nevertheless, the Panel considered that the setting of an AI is appropriate because of the beneficial effects of dietary fluoride on prevention of dental caries. The AI is based on epidemiological studies (performed before the 1970s showing an inverse relationship between the fluoride concentration of water and caries prevalence. As the basis for defining the AI, estimates of mean fluoride intakes of children via diet and drinking water with fluoride concentrations at which the caries preventive effect approached its maximum whilst the risk of dental fluorosis approached its minimum were chosen. Except for one confirmatory longitudinal study in US children, more recent studies were not taken into account as they did not provide information on total dietary fluoride intake, were potentially confounded by the use of fluoride-containing dental hygiene products, and did not permit a conclusion to be drawn on a dose-response relationship between fluoride intake and caries risk. The AI of fluoride from all sources (including non-dietary sources is 0.05 mg/kg body weight per day for both children and adults, including pregnant and lactating women. For pregnant and lactating women, the AI is based on the body weight before pregnancy and lactation. Reliable and representative data on the total fluoride intake of the European population are not available.

  20. Anticaries effect of dentifrices with calcium citrate and sodium trimetaphosphate

    Science.gov (United States)

    DELBEM, Alberto Carlos Botazzo; BERGAMASCHI, Maurício; RODRIGUES, Eliana; SASSAKI, Kikue Takebayashi; VIEIRA, Ana Elisa de Mello; MISSEL, Emilene Macario Coimbra

    2012-01-01

    Because of the growing concerns regarding fluoride ingestion by young children and dental fluorosis, it is necessary to develop new dentifrices. Objective The aim of this study was to evaluate the effect of dentifrices with calcium citrate (Cacit) and sodium trimetaphosphate (TMP) on enamel demineralization. Material and Methods Enamel blocks (n=70), previously selected through surface hardness analysis, were submitted to daily treatment with dentifrices diluted in artificial saliva and to a pH-cycling model. The fluoride concentration in dentifrices was 0, 250, 450, 550, 1,000 and 1,100 µg F/g. CrestTM was used as a positive control (1,100 mg F/g). Cacit (0.25%) and TMP (0.25%) were added to dentifrices with 450 and 1,000 µg F/g. Surface hardness was measured again and integrated loss of subsurface hardness and fluoride concentration in enamel were calculated. Parametric and correlation tests were used to determine difference (p0.05). Conclusions Dentifrices with 450 and 1,000 µg F/g, Cacit and TMP were as effective as a gold standard one. PMID:22437685

  1. Anticaries effect of dentifrices with calcium citrate and sodium trimetaphosphate

    Directory of Open Access Journals (Sweden)

    Alberto Carlos Botazzo Delbem

    2012-02-01

    Full Text Available Because of the growing concerns regarding fluoride ingestion by young children and dental fluorosis, it is necessary to develop new dentifrices. OBJECTIVE: The aim of this study was to evaluate the effect of dentifrices with calcium citrate (Cacit and sodium trimetaphosphate (TMP on enamel demineralization. MATERIAL AND METHODS: Enamel blocks (n=70, previously selected through surface hardness analysis, were submitted to daily treatment with dentifrices diluted in artificial saliva and to a pH-cycling model. The fluoride concentration in dentifrices was 0, 250, 450, 550, 1,000 and 1,100 µg F/g. CrestTM was used as a positive control (1,100 mg F/g. Cacit (0.25% and TMP (0.25% were added to dentifrices with 450 and 1,000 µg F/g. Surface hardness was measured again and integrated loss of subsurface hardness and fluoride concentration in enamel were calculated. Parametric and correlation tests were used to determine difference (p0.05. CONCLUSIONS: Dentifrices with 450 and 1,000 µg F/g, Cacit and TMP were as effective as a gold standard one.

  2. Chemical Species of Aluminum Lons in Acid Soils

    Institute of Scientific and Technical Information of China (English)

    XURENKOU; JIGUOLIANG

    1998-01-01

    Soil samples collected from several acid soils in Guangdong,Fujian,Zhejiang and Anhui provinces of the southern China were employded to characterize the chemical species of aluminum ions in the soils.The proportion or monoeric inorganic Al to total Al in soil solution was in the range of 19% to 70%,that of monomeric organlic Al (Al-OM) to total Al ranged from 7.7% to 69%,and that of the acid-soluble Al to total Al was generally smaller and was lower than 20% in most of the acid soils studied ,The Al-OM concentration in soil solution was postively correlated with the content of dissolved organic carbon(DOC) and aslo affected by the concentration of Al3+,The complexes of aluminum with fluoride(Al-F) were the predominant forms of inorganic Al,and the proportion of Al-F compexes to total inorganic Al increased with pH.Under strongly acid ondition,Al3+ was also a mjaor form of inorganic Al,and the proportio of Al3+ to total inorganic Al decreased with increasing pH.The,proportions of Al-OH and Al-SO4 complexes to total inorganic Al were small and were not larger than 10% in the most acid soils.The concentration of inorganic Al in solution depended largely on pH and the concentration of total F in soil solution,The concentrations of Al-OM,Al3+,Al-F and Al-OH complexes in topsoil were higher than those in subsoil and decreased with the increase in soil depth,The chemical species of aluminum ions were influenced by pH,The concentrations of Al-OM, Al3+,Al-F complexes and Al-OH complexes decreased with the increase in pH.

  3. A simple and colorimetric fluoride receptor and its fluoride-responsive organogel.

    Science.gov (United States)

    Yu, Xudong; Li, Yajuan; Yin, Yaobing; Yu, Decai

    2012-08-01

    In this paper, a new p-nitrophenylhydrozine-based anion receptor 1 containing cholesterol group had been designed and synthesized. It could selectively recognize fluoride among different anions tested with color changes from pale yellow to red for visual detection. Simultaneously, it could gel in cyclohexane, and the gel was also fluoride-responsive. When treated with TBAF (tetra-n-butylammonium fluoride), the gel could undergo gel-sol transition accompanied by color, morphology and surface changes. The binding mechanism had been investigated by UV-vis and (1)HNMR (proton nuclear magnetic resonance spectra) titrations. From SEM (scanning electron microscope), SAXS (small-angle X-ray scattering), IR (Infrared Spectroscopy) and CA (contact angle) experiments, it was indicated that the addition of F(-) could destroy the molecule assembly of host 1 in the gel state, thus resulting in the gel-to-sol transition due to the binding site competition effect. To the best of our knowledge, this was the simplest fluoride-responsive organogel with high selectivity.

  4. Degradation studies of transparent conductive electrodes on electroactive poly(vinylidene fluoride for uric acid measurements

    Directory of Open Access Journals (Sweden)

    Vanessa F Cardoso, Pedro Martins, Gabriela Botelho, Luis Rebouta, Senentxu Lanceros-Méndez and Graca Minas

    2010-01-01

    Full Text Available Biochemical analysis of physiological fluids using, for example, lab-on-a-chip devices requires accurate mixing of two or more fluids. This mixing can be assisted by acoustic microagitation using a piezoelectric material, such as the β-phase of poly(vinylidene fluoride (β-PVDF. If the analysis is performed using optical absorption spectroscopy and β-PVDF is located in the optical path, the material and its conductive electrodes must be transparent. Moreover, if, to improve the transmission of the ultrasonic waves to the fluids, the piezoelectric transducer is placed inside the fluidic structures, its degradation must be assessed. In this paper, we report on the degradation properties of transparent conductive oxides, namely, indium tin oxide (ITO and aluminum-doped zinc oxide, when they are used as electrodes for providing acoustic microagitation. The latter promotes mixing of chemicals involved in the measurement of uric acid concentration in physiological fluids. The results are compared with those for aluminum electrodes. We find that β-PVDF samples with ITO electrodes do not degrade either with or without acoustic microagitation.

  5. Effects of alternating periods of high- and low- fluoride ingestion on dairy cattle

    Energy Technology Data Exchange (ETDEWEB)

    Suttie, J.W.; Carlson, J.R.; Faltin, E.C.

    1972-01-01

    Two- and five-month old Holstein heifers were exposed to different intake patterns of dietary fluoride for 6 years. None of the fluoride treatments affected growth rate or reproduction. There was no consistent effect on milk production. Plasma fluoride concentrations closely followed current fluoride intake. Urinary fluoride concentrations varied with intake but remained elevated during low intake. Skeletal fluoride retention was directly related to total fluoride intake and not to pattern of intake. The degree of dental fluorosis was related to the amount of fluoride fed and to the plasma fluoride concentration at the time each incisor was developing. The most severe effects of fluoride ingestion were in high and low intake. These animals had severly worn molar teeth, extensive osteofluorosis, and they experienced periods of extreme lameness. Short periods of high fluoride intake balanced by periods of lower intake were more damaging to cattle than constant exposure to the same average yearly intake.

  6. Obstacles to extending fluoridation in the United States.

    Science.gov (United States)

    Neenan, M E

    1996-09-01

    The purpose of this paper is two-fold: (1) to describe the current extent of water fluoridation in the United States; (2) to address the major obstacles to attaining 75 per cent fluoridation by the year 2000. While 62.1 per cent of the US population has access to fluoridated public water systems, more than 32 million people need to be added to the fluoridation census, primarily from the cities. The legal framework for implementing fluoridation is considered at the state level; a review of fluoridation actions at the local level is presented. The impact of forces affecting the extension of fluoridation in the United States is described: (1) demographic trends--urbanisation, race, ethnicity, language, immigration, age, education levels, housing, income and poverty levels; (2) external environmental forces/political climate; (3) media influence on public opinion and public policy; (4) voter apathy/lack of awareness of the benefits of fluoridation; (5) perceptions of risks vs. benefits; (6) lack of political campaign skills; and (7) legal issues.

  7. A Process for Making Bulk Heavy Metal Fluoride Glasses.

    Science.gov (United States)

    This invention relates to the preparation of glasses, and, in particular, relates to the preparation of heavy metal fluoride glasses with...reproducible high optical qualities. Considerable effort has been expended to develop heavy metal fluoride glasses ( HMFG ) as a viable family of infrared

  8. Fluoride inhibits the response of bone cells to mechanical loading

    NARCIS (Netherlands)

    Willems, H.M.E.; van den Heuvel, E.G.H.M.; Castelein, S.; Keverling Buisman, J.; Bronckers, A.L.J.J.; Bakker, A.D.; Klein-Nulend, J.

    2011-01-01

    The response of bone cells to mechanical loading is mediated by the cytoskeleton. Since the bone anabolic agent fluoride disrupts the cytoskeleton, we investigated whether fluoride affects the response of bone cells to mechanical loading, and whether this is cytoskeleton mediated. The mechano-respon

  9. Computational investigation of the role of fluoride in Tamao oxidations

    DEFF Research Database (Denmark)

    Mader, Mary M.; Norrby, Per-Ola

    2002-01-01

    The Tamao oxidation of alkoxysilanes was investigated computationally to determine the role of fluoride. a key additive. in this reaction. A sequence of fluoride equilibria as well as possible transition states. mediated by basic and neutral peroxide, respectively, were examined, and a potential...

  10. Mechanisms of action of fluoride for caries control

    NARCIS (Netherlands)

    Buzalaf, M.A.R.; Pessan, J.P.; Honório, H.M.; ten Cate, J.M.; Buzalaf, M.A.R.

    2011-01-01

    Fluoride was introduced into dentistry over 70 years ago, and it is now recognized as the main factor responsible for the dramatic decline in caries prevalence that has been observed worldwide. However, excessive fluoride intake during the period of tooth development can cause dental fluorosis. In o

  11. KINETICS OF SORPTION OF FLUORIDE ON CALCINED MAGNESITE IN BATCH

    DEFF Research Database (Denmark)

    Singano, J. J.; Mashauri, D. A.; Mtalo, F. W.;

    1997-01-01

    A series of sorption of fluoride on calcined magnesite are obtained from thermostatic pH-chemostat and jar test experiments. The fluoride removal is observed not to start instantly, as normal, but after a lag time of up to ½ an hour of contact time. A model for sorption kinetics is developed, bas...

  12. Poisoning by coal smoke containing arsenic and fluoride

    Energy Technology Data Exchange (ETDEWEB)

    An, D.; He, Y.G.; Hu, Q.X. [Guizhou Sanitary and Epidemiological Station, Guiyang (China)

    1997-02-01

    An investigation was made into a disease involving skin pigmentation, keratosis of the hands and feet, dental discoloration, and generalized bone and joint pain, stiffness and rigidity, in the village of Bazhi, Zhijin County, Ghizhou Province, People`s Republic of China. Measurements were made of the arsenic and fluoride levels of coal, water, air, food, urine and hair in Bazhi and a control village, Xinzhai, in which coal with a low arsenic content was used. Up to 188 people, including children, in Bazhi and 752 in Xinzhai, were examined for the presence of chronic arsenium, skeletal fluorosis, dental fluorosis and electrocardiogram abnormalities. The coal in Bazhi was found to contain high levels of arsenic and fluoride resulting, after burning in homes without an adequate chimney systems, in pollution of air and food with arsenic and fluoride. The coal in Xinzhai did not cause arsenic pollution but did produce a higher level of fluoride pollution. It was concluded that the endemic disease in Bazhi was caused by pollution by coal smoke containing arsenic and fluoride. It is suggested that arsenic may act synergistically with fluoride so that a lower level of fluoride may produce fluoride toxicity with dental and skeletal fluorosis.

  13. Anti Streptococcus mutans non fluoride and fluoride containing sealants after adding nano-silver particles

    Directory of Open Access Journals (Sweden)

    Maryam Ghasempour

    2014-04-01

    Full Text Available   Background and Aims: Since recurrent caries are one of the major causes of failure in resin restorations, the production of antibacterial resin composites was always under investigation. The aim of this study was to evaluate the efficacy of fissure sealants containing nanosilver particles against the Streptococcus mutans.   Materials and Methods: In this experimental study, the antibacterial properties of two sealants (with fluoride (Clinpro 3M and without fluoride (Concise 3M was investigated with 0, 0.01, 0.02, 0.03, 0.04, 0.05% w/w after adding nano-silver using direct contact test. Sealants formed on the walls of 500ml micro tube and after curing, they left in contact with bacterial suspension. In periods of 3, 24, 48h, a 10 µl volume of liquid medium was placed in blood agar culture and after 24 h incubation at 37ºC, the number of S.mutans colony was counted by colony counter. Data were analyzed using ANOVA andT-test.   Results: Results reported sealants with fluoride comparing to non fluoride ones had significant effect on inhibition of S.mutans growth (P<0.001. The direct contact test demonstrated that by increasing the amount of nano particles, the bacterial growth was significantly diminished (P<0.001.   Conclusion: While sealants with fluoride demonstrated antibacterial effect, sealants with incorporation of higher weight percentage of nanosilver particles, had stronger and more significant antibacterial effect in direct contact test.

  14. Fluoride microresonators for mid-IR applications

    CERN Document Server

    Grudinin, Ivan S; Yu, Nan

    2016-01-01

    We study crystalline fluoride microresonators for mid-infrared applications. Whispering gallery mode resonators were fabricated with BaF$_2$, CaF$_2$ and MgF$_2$ crystals. The quality factors were measured at wavelengths of 1.56 {\\mu}m and 4.58 {\\mu}m. The impacts of fabrication technique, impurities, multiphonon absorption and surface water are investigated. It is found that MgF2 resonators have room temperature Q factor of $8.3\\times 10^6$ at wavelength of 4.58 {\\mu}m, limited by multiphonon absorption.

  15. Hydrogen fluoride overtone technology: Status review

    Science.gov (United States)

    Duncan, William A.; Patterson, Stanley P.; Graves, Bruce R.; Holloman, Miles E.; Sollee, Jeffrey L.

    The hydrogen fluoride (HF) overtone chemical laser concept is being developed as a shorter wavelength alternative to the well known HF fundamental chemical laser to achieve higher brightness space-based laser platforms. This paper provides a brief review of the overtone experimental data base and then concentrates on the design of versatile gain generator hardware for optimizing the Hypersonic Low-Temperature (HYLTE) nozzle concept for HF overtone laser performance. The paper also describes a recent high power demonstration of overtone lasing on a scalable gain generator device that is directly traceable to a space-based laser weapon, utilizing uncooled resonator optics.

  16. The status of community water fluoridation in the United States.

    Science.gov (United States)

    Easley, M W

    1990-01-01

    Community water fluoridation has served the American public extremely well as the cornerstone of dental caries prevention activities for 45 years. The dental and general health benefits associated with the ingestion of water-borne fluorides have been well known by researchers for an even longer period. Continued research has repeatedly confirmed the safety, effectiveness, and efficiency of community water fluoridation in preventing dental caries for Americans regardless of age, race, ethnicity, religion, educational status, or socioeconomic level. Despite the obvious benefits associated with this proven public health measure, slow progress has been made toward achieving the 1990 national fluoridation objectives as listed in "Promoting Health/Preventing Disease: Objectives for the Nation." This paper documents the lagging pace of community fluoridation by reviewing and analyzing data reported in "Fluoridation Census, 1985," a document published in late 1988 by the Public Health Service's Centers for Disease Control. Failure to attain the 1990 objectives is attributable to a combination of circumstances, including their low priority within many local, State, and Federal health agencies, inadequate funding at all levels of government, lack of a coordinated and focused national fluoridation effort, failure of most States to require fluoridation, lack of Federal legislation mandating fluoridation, general apathy of most health professional organizations toward fluoridation, misconceptions by the public about effectiveness and safety and, finally, unrelenting opposition by a highly vocal minority of the lay public. In addition, fluoridation successes have not been consistent among States, with wide variation in accomplishments documented in the reported data.While fluoridation still is one of the most cost effective public health measures available to local,State, and Federal public health agencies, it remains significantly underused nearly a half century after its

  17. Invisible Display in Aluminum

    DEFF Research Database (Denmark)

    Prichystal, Jan Phuklin; Hansen, Hans Nørgaard; Bladt, Henrik Henriksen

    2005-01-01

    Bang & Olufsen a/s has been working with ideas for invisible integration of displays in metal surfaces. Invisible integration of information displays traditionally has been possible by placing displays behind transparent or semitransparent materials such as plastic or glass. The wish for an integ...... be obtained by shining light from the backside of the workpiece. When there is no light from the backside, the front surface seems totally untouched. This was achieved by laser ablation with ultra-short pulses.......Bang & Olufsen a/s has been working with ideas for invisible integration of displays in metal surfaces. Invisible integration of information displays traditionally has been possible by placing displays behind transparent or semitransparent materials such as plastic or glass. The wish...... for an integrated display in a metal surface is often ruled by design and functionality of a product. The integration of displays in metal surfaces requires metal removal in order to clear the area of the display to some extent. The idea behind an invisible display in Aluminum concerns the processing of a metal...

  18. Anodized aluminum on LDEF

    Science.gov (United States)

    Golden, Johnny L.

    1993-01-01

    A compilation of reported analyses and results obtained for anodized aluminum flown on the Long Duration Exposure Facility (LDEF) was prepared. Chromic acid, sulfuric acid, and dyed sulfuric acid anodized surfaces were exposed to the space environment. The vast majority of the anodized surface on LDEF was chromic acid anodize because of its selection as a thermal control coating for use on the spacecraft primary structure, trays, tray clamps, and space end thermal covers. Reports indicate that the chromic acid anodize was stable in solar absorptance and thermal emittance, but that contamination effects caused increases in absorptance on surfaces exposed to low atomic oxygen fluences. There were some discrepancies, however, in that some chromic acid anodized specimens exhibited significant increases in absorptance. Sulfuric acid anodized surfaces also appeared stable, although very little surface area was available for evaluation. One type of dyed sulfuric acid anodize was assessed as an optical baffle coating and was observed to have improved infrared absorptance characteristics with exposure on LDEF.

  19. The effective use of fluorides in public health

    DEFF Research Database (Denmark)

    Jones, Sheila; Burt, Brian A; Petersen, Poul Erik

    2005-01-01

    Dental caries remain a public health problem for many developing countries and for underprivileged populations in developed countries. This paper outlines the historical development of public health approaches to the use of fluoride and comments on their effectiveness. Early research and developm......Dental caries remain a public health problem for many developing countries and for underprivileged populations in developed countries. This paper outlines the historical development of public health approaches to the use of fluoride and comments on their effectiveness. Early research...... and their families, and the issue of cost. We recommend that a community should use no more than one systemic fluoride (i.e. water or salt or milk fluoridation) combined with the use of fluoride toothpastes, and that the prevalence of dental fluorosis should be monitored in order to detect increases in or higher...

  20. Fluoride use in Controlling Dental Caries and Fluorosis

    Directory of Open Access Journals (Sweden)

    Gaurav Solanki

    2012-07-01

    Full Text Available Policy were introduced to control fluoride exposure and to reduce the prevalence of fluorosis. The study aimed of describing the prevalence, severity and risk factors for fluorosis, and to describe the trend of fluorosis among Indian children. The study also aimed of exploring the effect of the change in fluoride exposure on dental fluorosis and caries. Establishing an appropriate use of fluoride toothpaste could be successful in reducing fluorosis without a significant increase in caries experience. The use of fluorides for oral health has always involved a balance between the protective benefit against dental caries and the risk of developing fluorosis. The link between fluoride and dental health was established to determining the causes of dental fluorosis or enamel mottling. Fluorosis in Indian children was highly prevalent in the early 1990s.

  1. Assessment of groundwater quality with respect to fluoride.

    Science.gov (United States)

    Salve, P R; Maurya, A; Kumbhare, P S; Ramteke, D S; Wate, S R

    2008-09-01

    The study was conducted in the summer season (April-May 2007). The fluoride concentration along with physico-chemical parameters in ground water samples was determined in various villages of Kadi tehsil at Mehsana district of Gujarat state (India), since in most of the villages it is the only source of drinking water. The fluoride concentrations in these villages varied from 0.94 to 2.81 mg/L (1.37+/-0.56) with highest fluoride level at Visalpur (2.08 mg/L) and lowest at Adaraj (0.91 mg/L). There was found a positive correlation of pH with fluoride and a negative relationship of fluoride with bicarbonate which is generally observed in deep ground water.

  2. The hardness and chemical changes in demineralized primary dentin treated by fluoride and glass ionomer cement

    Directory of Open Access Journals (Sweden)

    Gisele Fernandes DIAS

    Full Text Available Abstract Background Fluoride plays an important role in the control of dental caries. Aim To evaluate the chemical exchange between restoration of glass ionomer cement of high viscosity (GIC and primary dentin with application of sodium fluoride (NaF 2% through changes in hardness from uptake of calcium, phosphate and fluoride. Material and method Class I cavities were prepared in 40 sound primary molars, and the sample was divided into two groups (n=20 according to dentin condition: sound (1 and demineralized (2. Sub-groups (n=10 were formed to investigate the isolated action of the GIC or the association with NaF (F. This in vitro study examined the chemical exchange under two conditions, sound and demineralized dentin (pH cycling, to simulate the occurrence of mineral loss for the caries lesion. G1 and G2 received GIC restoration only; groups G1F and G2F received NaF before GIC restoration. The specimens were prepared for Knoop hardness test and micro-Raman spectroscopy. A two-way ANOVA test (α = 0.05 was used for statistical analysis. Micro-Raman data were qualitatively described. Result Increased hardness was observed in all the sites of direct contact with GIC in sound and demineralized dentin for all groups (p0.05. In the evaluation of micro-Raman, direct contact between GIC and dentin for sound and demineralized dentin resulted in increased peaks of phosphate. Conclusion The exchange between GIC and demineralized dentin may induce changes of mechanical properties of the substrate, and uptake of mineral ions (phosphate occurs without the influence of NaF.

  3. Milk fluoridation for the prevention of dental caries

    Directory of Open Access Journals (Sweden)

    Jolán Bánóczy

    2013-11-01

    Full Text Available The aim of this review is to give an overview of 55 years experience of milk fluoridation and draw conclusions about the applicability of the method. Fluoridated milk was first investigated in the early 1950s, almost simultaneously in Switzerland, the USA and Japan. Stimulated by the favourable results obtained from these early studies, the establishment of The Borrow Dental Milk Foundation (subsequently The Borrow Foundation in England gave an excellent opportunity for further research, both clinical and non-clinical, and a productive collaboration with the World Health Organization which began in the early 1980s. Numerous peer-reviewed publications in international journals showed clearly the bioavailability of fluoride in various types of milk. Clinical trials were initiated in the 1980s – some of these can be classed as randomised controlled trials, while most of the clinical studies were community preventive programmes. Conclusion. These evaluations showed clearly that the optimal daily intake of fluoride in milk is effective in preventing dental caries. The amount of fluoride added to milk depends on background fluoride exposure and age of the children: commonly in the range 0.5 to 1.0 mg per day. An advantage of the method is that a precise amount of fluoride can be delivered under controlled conditions. The cost of milk fluoridation programmes is low, about € 2 to 3 per child per year. Fluoridation of milk can be recommended as a caries preventive measure where the fluoride concentration in drinking water is suboptimal, caries experience in children is significant, and there is an existing school milk programme.

  4. Gas evolution behavior of aluminum in mortar

    Energy Technology Data Exchange (ETDEWEB)

    Hashizume, Shuji; Matsumoto, Junko; Banba, Tsunetaka [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1996-10-01

    As a part of study of leaching behavior for solidified dry low level radioactive waste, gas evolution behavior of aluminum in mortar was investigated, and a plan of our research was proposed. The effect of pH on corrosion rate of aluminum, corrosion product, time dependency of corrosion rate of aluminum in mortar, change of corrosion mechanism, the effects of Na, Ca and Cl ions on corrosion rate of aluminum in mortar and corrosion behavior of aluminum when aluminum was used as sacrificed anode in reinforced concrete were previously clarified. Study of the effects of environmental factors such as pH, kind of ions and temperature on gas evolution behavior of aluminum and the effect of aluminum/carbon steel surface ratio no gas evolution behavior of aluminum were planed. (author). 75 refs.

  5. Low-aluminum content iron-aluminum alloys

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K.; Goodwin, G.M.; Alexander, D.J. [and others

    1995-06-01

    The low-aluminum-content iron-aluminum program deals with the development of a Fe-Al alloy with aluminum content such as a produce the minimum environmental effect at room temperature. The FAPY is an Fe-16 at. % Al-based alloy developed at the Oak Ridge National Laboratory as the highest aluminum-containing alloy with essentially no environmental effect. The chemical composition for FAPY in weight percent is: aluminum = 8.46, chromium = 5.50, zirconium = 0.20, carbon = 0.03, molybdenum = 2.00, yttrium = 0.10 and iron = 83.71. The ignots of the alloy can be hot worked by extrusion, forging, and rolling processes. The hot-worked cast structure can be cold worked with intermediate anneals at 800{degrees}C. Typical room-temperature ductility of the fine-grained wrought structure is 20 to 25% for this alloy. In contrast to the wrought structure, the cast ductility at room temperature is approximately 1% with a transition temperature of approximately 100 to 150{degrees}C, above which ductility values exceed 20%. The alloy has been melted and processed into bar, sheet, and foil. The alloy has also been cast into slabs, step-blocks of varying thicknesses, and shapes. The purpose of this section is to describe the welding response of cast slabs of three different thicknesses of FAPY alloy. Tensile, creep, and Charpy-impact data of the welded plates are also presented.

  6. Decode the Sodium Label Lingo

    Science.gov (United States)

    ... For Preschooler For Gradeschooler For Teen Decode the Sodium Label Lingo Published January 24, 2013 Print Email Reading food labels can help you slash sodium. Here's how to decipher them. "Sodium free" or " ...

  7. Chronic fluoride exposure-induced testicular toxicity is associated with inflammatory response in mice.

    Science.gov (United States)

    Wei, Ruifen; Luo, Guangying; Sun, Zilong; Wang, Shaolin; Wang, Jundong

    2016-06-01

    Previous studies have indicated that fluoride (F) can affect testicular toxicity in humans and rodents. However, the mechanism underlying F-induced testicular toxicity is not well understood. This study was conducted to evaluate the sperm quality, testicular histomorphology and inflammatory response in mice followed F exposure. Healthy male mice were randomly divided into four groups with sodium fluoride (NaF) at 0, 25, 50, 100 mg/L in the drinking water for 180 days. At the end of the exposure, significantly increased percentage of spermatozoa abnormality was found in mice exposed to 50 and 100 mg/L NaF. Disorganized spermatogenic cells, vacuoles in seminiferous tubules and loss and shedding of sperm cells were also observed in the NaF treated group. In addition, chronic F exposure increased testicular interleukin-17(IL-17), interleukin-17 receptor C (IL-17RC), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in transcriptional levels, as well as IL-17 and TNF-α levels in translational levels. Interestingly, we observed that F treated group elevated testicular inducible nitric oxide synthase (iNOS) mRNA level and nitric oxide (NO) concentration. Taken together, these results indicated that testicular inflammatory response could contribute to chronic F exposure induced testicular toxicity in mice.

  8. Fluoride-induced histopathology and synthesis of stress protein in liver and kidney of mice.

    Science.gov (United States)

    Chattopadhyay, Ansuman; Podder, Santosh; Agarwal, Soumik; Bhattacharya, Shelley

    2011-04-01

    Selective low (15 mg sodium fluoride (NaF)/L) and relatively high (150 mg NaF/L) doses of in vivo fluoride (F) treatment to Swiss albino mice through drinking water elicited organ-specific toxicological response. All the F-exposed groups showed severe alterations in both liver and kidney architectures, but there was no significant change in the rate of water consumption and body weight. Vacuolar degeneration, micronecrotic foci in the hepatocytes, and hepatocellular hypertrophy were evident in the mice exposed to low dose (15 mg NaF/L for 30 days) while sinusoidal dilation with enlarged central vein surrounded by deep-blue erythrocytes were preponderant when treated with the same dose for a period of 90 days. Blood filled spaces, disintegration of tubular epithelium, and atrophy of glomeruli were also recorded in the kidney of the same treatment group. Change in reduced glutathione level (GSH), glutathione-s-transferase (GST) activity, malondialdehyde (MDA) production in both liver and kidney, disturbances in liver function, induction of heat shock protein 70 (Hsp 70) expression in kidney and its down regulation in liver were positively correlated with histopathological lesion.

  9. Preparation of fluoride substituted apatite cements as the building blocks for tooth enamel restoration

    Energy Technology Data Exchange (ETDEWEB)

    Wei Jie [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Inter-disciplinary Studies, Peking University, Beijing 100871 (China); Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Wang Jiecheng; Liu Xiaochen [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Inter-disciplinary Studies, Peking University, Beijing 100871 (China); Ma Jian [Hospital of Stomatology, Tongji University, Shanghai 200072 (China); Liu Changsheng [Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Fang Jing, E-mail: biomater2006@yahoo.com.cn [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Inter-disciplinary Studies, Peking University, Beijing 100871 (China); Wei Shicheng, E-mail: nic7505@263.net [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Inter-disciplinary Studies, Peking University, Beijing 100871 (China) and School and Hospital of Stomatology, Peking University, Beijing 100081 (China)

    2011-06-15

    Fluoride substituted apatite cement (fs-AC) was synthesized by using the cement powders of tetracalcium phosphate (TTCP) and sodium fluoride (NaF), and the cement powders were mixed with diluted phosphoric acid (H{sub 3}PO{sub 4}) as cement liquid to form fs-AC paste. The fs-AC paste could be directly filled into the carious cavities to repair damaged dental enamel. The results indicated that the fs-AC paste was changed into fluorapatite crystals with the atom molar ratio for calcium to phosphorus of 1.66 and the F ion amount of 3 wt% after self-hardening for 2 days. The solubility of fs-AC in Tris-HCl solution (pH 6) was slightly lower than hydroxyapatite cement (HAC) that was similar to the apatite in enamel, indicating the fs-AC was much insensitive to the weakly acidic solution than the apatite in enamel. The fs-AC was tightly combined with the enamel surface because of the chemical reaction between the fs-AC and the apatite in enamel after the caries cavities was filled with fs-AC. The extracts of fs-AC caused no cytotoxicity on L929 cells, which satisfied the relevant criterion on dental biomaterials, revealing good cytocompatibility. The fs-AC had potential prospect for the reconstitution of carious lesion of dental enamel.

  10. Preparation of fluoride substituted apatite cements as the building blocks for tooth enamel restoration

    Science.gov (United States)

    Wei, Jie; Wang, Jiecheng; Liu, Xiaochen; Ma, Jian; Liu, Changsheng; Fang, Jing; Wei, Shicheng

    2011-06-01

    Fluoride substituted apatite cement (fs-AC) was synthesized by using the cement powders of tetracalcium phosphate (TTCP) and sodium fluoride (NaF), and the cement powders were mixed with diluted phosphoric acid (H 3PO 4) as cement liquid to form fs-AC paste. The fs-AC paste could be directly filled into the carious cavities to repair damaged dental enamel. The results indicated that the fs-AC paste was changed into fluorapatite crystals with the atom molar ratio for calcium to phosphorus of 1.66 and the F ion amount of 3 wt% after self-hardening for 2 days. The solubility of fs-AC in Tris-HCl solution (pH 6) was slightly lower than hydroxyapatite cement (HAC) that was similar to the apatite in enamel, indicating the fs-AC was much insensitive to the weakly acidic solution than the apatite in enamel. The fs-AC was tightly combined with the enamel surface because of the chemical reaction between the fs-AC and the apatite in enamel after the caries cavities was filled with fs-AC. The extracts of fs-AC caused no cytotoxicity on L929 cells, which satisfied the relevant criterion on dental biomaterials, revealing good cytocompatibility. The fs-AC had potential prospect for the reconstitution of carious lesion of dental enamel.

  11. APPLICATION OF VACUUM SALT DISTILLATION TECHNOLOGY FOR THE REMOVAL OF FLUORIDE AND CHLORIDE FROM LEGACY FISSILE MATERIALS

    Energy Technology Data Exchange (ETDEWEB)

    Pierce, R.; Peters, T.

    2011-11-01

    Between September 2009 and January 2011, the Savannah River National Laboratory (SRNL) and the Savannah River Site (SRS) HB-Line Facility designed, developed, tested, and successfully deployed a production-scale system for the distillation of sodium chloride (NaCl) and potassium chloride (KCl) from plutonium oxide (PuO{sub 2}). Subsequent efforts adapted the vacuum salt distillation (VSD) technology for the removal of chloride and fluoride from less-volatile halide salts at the same process temperature and vacuum. Calcium chloride (CaCl{sub 2}), calcium fluoride (CaF{sub 2}), and plutonium fluoride (PuF{sub 3}) were of particular concern. To enable the use of the same operating conditions for the distillation process, SRNL employed in situ exchange reactions to convert the less-volatile halide salts to compounds that facilitated the distillation of halide without removal of plutonium. SRNL demonstrated the removal of halide from CaCl{sub 2}, CaF{sub 2} and PuF{sub 3} below 1000 C using VSD technology.

  12. A time-related study of intake pattern of fluoride tablets among Swedish preschoolchildren and parental attitudes.

    Science.gov (United States)

    Widenheim, J

    1982-12-01

    The principal aim of this study was to investigate sodium fluoride tablet consumption and its variability over a particular period. Information was collected from questionnaires sent in 1975 and 1980 to all parents of children born in Lund, Sweden, in 1967 and 1972 and still resident in this city, where drinking water contains 0.2 parts/10(6) F. The results showed that 69% of the children born in 1967 (n = 373) had taken tablets at some time during the period 1/2-7 years of age and that 13% had consumed tablets regularly for minimum 5 1/2 years. The corresponding figures for children born in 1972 (n = 474) were 51% and 12%, respectively. Sporadic consumers were responsible for the main difference (15%) between the two populations. A selection of parents from the 1975 and 1980 materials was made with respect to duration of consumption and level of parental education. The frequency of non-users had increased mostly among families with a higher parental education. For those parents who had not given their children tablets or had ceased to do so, the 1980 inquiry was enlarged with questions about reasons for this. The item marked most frequently (56%) implied that fluoride may be dangerous to swallow. Another 13% responded that they had not been recommended to give their children tablets. However, topical use of fluoride in toothpaste during preschool age and in mouthrinses from 6 years of age is, according to the present study, well accepted.

  13. 76 FR 19001 - Sulfuryl Fluoride; Addendum to Proposed Order Granting Objections to Tolerances and Denying...

    Science.gov (United States)

    2011-04-06

    ... treatments and for structural fumigation for which there is significant sulfuryl fluoride use and no readily... fluoride/fluoride tolerances for rice commodities associated with direct fumigation of rice that were... phosphine) rather than sulfuryl fluoride. (See Office of Prevention, Pesticides, and Toxic Substances,...

  14. Scaleable Clean Aluminum Melting Systems

    Energy Technology Data Exchange (ETDEWEB)

    Han, Q.; Das, S.K. (Secat, Inc.)

    2008-02-15

    The project entitled 'Scaleable Clean Aluminum Melting Systems' was a Cooperative Research and Development Agreements (CRADAs) between Oak Ridge National Laboratory (ORNL) and Secat Inc. The three-year project was initially funded for the first year and was then canceled due to funding cuts at the DOE headquarters. The limited funds allowed the research team to visit industrial sites and investigate the status of using immersion heaters for aluminum melting applications. Primary concepts were proposed on the design of furnaces using immersion heaters for melting. The proposed project can continue if the funding agency resumes the funds to this research. The objective of this project was to develop and demonstrate integrated, retrofitable technologies for clean melting systems for aluminum in both the Metal Casting and integrated aluminum processing industries. The scope focused on immersion heating coupled with metal circulation systems that provide significant opportunity for energy savings as well as reduction of melt loss in the form of dross. The project aimed at the development and integration of technologies that would enable significant reduction in the energy consumption and environmental impacts of melting aluminum through substitution of immersion heating for the conventional radiant burner methods used in reverberatory furnaces. Specifically, the program would couple heater improvements with furnace modeling that would enable cost-effective retrofits to a range of existing furnace sizes, reducing the economic barrier to application.

  15. Antimicrobial and cytotoxicity evaluation of colloidal chitosan - silver nanoparticles - fluoride nanocomposites.

    Science.gov (United States)

    Freire, Priscila L L; Albuquerque, Allan J R; Farias, Isabela A P; da Silva, Teresinha Gonçalves; Aguiar, Jaciana Santos; Galembeck, André; Flores, Miguel A P; Sampaio, Fabio C; Stamford, Thayza Christina Montenegro; Rosenblatt, Aronita

    2016-12-01

    The present study aimed to evaluate the antimicrobial activity and cytotoxicity of colloidal chitosan - silver nanoparticle - fluoride nanocomposites (CChAgNpFNc), with different silver nanoparticle shapes and sizes. The syntheses of CChAgNpFNc were performed with silver nitrate added to a chitosan solution, addition of a sodium borohydride solution and solid sodium fluoride. Solution of ascorbic acid was added to synthesize larger silver nanoparticles. CChAgNpFNc obtained: S1- 100% spherical, 8.7±3.1nm; S2- 97% spherical, 15.0±7.9nm and 2.5% triangular, 22.2±9.5nm; S3- 77.3% spherical, 31.8±10.4nm, 15.9% triangular, 27.1±10.1nm and 6.8% elliptical, 33.2±7.8nm; and S4- 75.2% spherical, 43.2±14.3nm; 23.3% triangular 38.2±14.8nm, and 1.5% elliptical 38.4±11.6nm. The CChAgNpFNc showed antimicrobial activity against Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa and Candida albicans, by microdilution technique. The influence on the growth of microorganisms was evaluated using a fluorescence assay, and showed an increasing lag phase and a decreasing log phase. Cytotoxicity was investigated using Artemia salina and MTT assays. The S3 and S4 samples exhibited low cytotoxicity. The S1 and S2 samples inhibited murine macrophages and revealed lethal dose concentrations above 1000mg/mL that were classified as moderately toxic. Thus, CChAgNpFNc are potential options for the control of multiple-drug-resistant microorganisms and do not represent substantial risks to human health.

  16. [Sodium and hypertension].

    Science.gov (United States)

    de Wardener, H E

    1996-09-01

    Over several million years the human race was programmed to eat a diet which contained about 15 mmol of sodium (1 g of sodium chloride) per day. It is only five to ten thousand years ago that we became addicted to salt. Today we eat about 150 mmol of sodium (9-12 g of salt) per day. It is now apparent that this sudden rise in sodium intake (in evolutionary terms) is the most likely cause for the rise in blood pressure with age that occurs in the majority of the world's population. Those which consume less than 60 mmol/day do not develop hypertension. The reason for the rise in sodium intake is not known but it is probable that an important stimulus was the discovery that meat could be preserved by immersion into a concentrated salt solution. This seemingly miraculous power endowed salt with such magical and medicinal qualities that it became a symbol of goodness and health. It was not until 1904 Ambard and Beaujard suggested that on the contrary dietary salt could be harmful and raise the blood pressure. At first the idea did not prosper and it continues to be opposed by a diminishing band. The accumulated evidence that sodium intake is related to the blood pressure in normal man and animals and in inherited forms of hypertension has been obtained from experimental manipulations and studies of human populations. The following observation links sodium and hypertension. An increase in sodium intakes raises the blood pressure of the normal rat, dog, rabbit, baboon, chimpanzee and man. Population studies have demonstrated a significant correlation between sodium intake and the customary rise in blood pressure with age. The development of hypertensive strains of rats has revealed that the primary genetic lesion which gives rise to hypertension resides in the kidney where it impairs the urinary excretion of sodium. There is similar but less convincing evidence in essential hypertension. The kidney in both essential hypertension and hypertensive strains of rats share a

  17. FLUORIDE SORPTION USING MORRINGA INDICA-BASED ACTIVATED CARBON

    Directory of Open Access Journals (Sweden)

    G. Karthikeyan, S. Siva Ilango

    2007-01-01

    Full Text Available Batch adsorption experiments using activated carbon prepared from Morringa Indica bark were conducted to remove fluoride from aqueous solution. A minimum contact time of 25 min was required for optimum fluoride removal. The influence of adsorbent, dose, pH, co-ions (cations and anions on fluoride removal by the activated carbon has been experimentally verified. The adsorption of fluoride was studied at 30 C, 40 C and 50 C. The kinetics of adsorption and adsorption isotherms at different temperatures were studied. The fluoride adsorption obeyed both Langmuir and Freundlich isotherms and followed a pseudo first order kinetic model. The thermodynamic studies revealed that the fluoride adsorption by Morringa Indica is an endothermic process indicating an increase in sorption rate at higher temperatures. The negative values of G indicate the spontaneity of adsorption. SEM and XRD studies confirmed the surface morphological characteristics of the adsorbent and the deposition of fluoride on the surface of the material.

  18. High Fluoride Dentifrices for Elderly and Vulnerable Adults

    DEFF Research Database (Denmark)

    Ekstrand, Kim Rud

    2016-01-01

    The primary aim of this work is to present the available evidence that toothpastes containing >1,500 ppm fluoride (2,500-2,800 and 5,000 ppm F) provide an additional caries preventive effect on root caries lesions in elderly patients compared to traditional dentifrices (1,000-1,450 ppm F). The se......The primary aim of this work is to present the available evidence that toothpastes containing >1,500 ppm fluoride (2,500-2,800 and 5,000 ppm F) provide an additional caries preventive effect on root caries lesions in elderly patients compared to traditional dentifrices (1,000-1,450 ppm F......). The secondary aim of this paper is to discuss why high fluoride dentifrices in general should perform better than traditional F-containing toothpaste. When examining the few studies that have considered the preventive benefits of high fluoride products on root caries the relative risk appears to be around 0.......5, and the risk can thus be halved by exchanging traditional F-containing toothpaste for toothpaste containing 5,000 ppm F. There is reasonable evidence that high fluoride dentifrices significantly increase the fluoride concentration in saliva during the day and the fluoride concentration in plaque compared...

  19. Synthesis of nanocrystalline mixed metal fluorides in nonaqueous medium

    Indian Academy of Sciences (India)

    Neetu Tyagi; Epsita Ghanti; Nikesh Gupta; N P Lalla; Rajamani Nagarajan

    2009-12-01

    Synthesis of mixed metal fluorides of the general formula, KMF3 (M = Mg, Mn, Co, Ni, Cu and Zn), possessing perovskite structure was investigated in non-aqueous medium. The fluorides were characterized by powder X-ray diffraction, FT–IR spectroscopy, thermal analysis, SEM and TEM. Monophasic cubic phases were obtained for the central metal ions such as Mg, Mn, Co, Ni, and Zn and a tetragonally distorted phase was observed for Cu. The usage of non-aqueous medium is advantageous for the bulk synthesis of these fluorides, since it eliminated the generation and handling of the hazardous HF that has usually been encountered during aqueous preparations. The average crystallite size of the fluorides obtained by this approach was estimated to be in the range of 9–30 nm. SEM micrographs of KZnF3 showed cubic morphology of perovskite phases. TEM studies on KCuF3 confirmed the presence of tetragonal distortion. The fluoride content was determined by titrimetry and found to be nearly stoichiometric. Some of these fluorides were found to be thermally stable up to 225°C in air. These fluorides were employed as fluorinating agents in organic fluorination reactions, thereby suggesting their possible utilization for selective fluorination of aliphatic and aromatic hydrofluorocarbons (HFCs) that are industrially relevant.

  20. A test chamber for experimental hydrogen fluoride exposure in humans.

    Science.gov (United States)

    Søstrand, P; Kongerud, J; Eduard, W; Nilsen, T; Skogland, M; Boe, J

    1997-07-01

    An inhalation chamber was built to perform experimental studies with hydrogen fluoride (HF), other gases, and particulate matter. The present study sought to describe a new gas delivery system and the distribution and concentration of HF gas in the chamber. The aluminum chamber has a volume of 19.2 m3 and a variable ventilation rate of about 1 to 10 air changes per hour. The negative pressure difference between the chamber and outside air can be regulated from 0 to 300 Pa. HF was fed at concentrations of up to 4000 mg/m3 directly into the ventilation duct feeding the chamber through openings with diameters as small as 50 microns, oriented opposite to the airflow. Gas flow was varied from about 0.1 dm3/min at a pressure of 4 atm. The dilution factor of HF concentration from cylinder to chamber was on the order of 10(3) to 10(4). The standard deviation (SD) of the HF concentrations at a fixed measurement point during a 1-hour test was typically 0.05 mg/m3 at a time-weighted average (TWA) concentration of 2.66 mg/m3. The SD of the TWA HF concentrations at six locations in the chamber was typically 0.05 mg/m3 and 0.29 mg/m3 at 0.61 and 3.46 mg/m3, respectively. Human exposure could be predicted from calculations based on ventilation data, gas flow, and observed ratio between calculated and measured concentrations. When the target exposure concentration was 1.5 mg/m3, the measured mean exposure concentration was typically 1.54 mg/m3 (range: 1.4-1.7 mg/m3, SD 0.09 mg/m3, n = 8). The chamber is well-suited for inhalation studies in humans. Chamber atmosphere was controlled and has proved to be stable and homogeneous, even in tests with HF, a highly reactive gas in the class of superacids.